Clarence Lewis Barnhart was an American lexicographer best known for editing the Thorndike-Barnhart series of graded dictionaries, published by Scott Foresman & Co. which were based on word lists and concepts of definition developed by psychological theorist Edward Thorndike. Barnhart subsequently revised and expanded the series and with the assistance of his sons, maintaining them through the 1980s. Barnhart attended the University of Chicago and studied under noted linguist and primary founder of the Linguistic Society of America, Leonard Bloomfield. Barnhart was influenced by Bloomfield's approach to learning which included developing word lists based on frequency of use and citation files based on real-world examples. In 1929 Barnhart joined book publisher Scott, Foresman & Co. becoming an editor. Scott, Foresman paid for portions of his education in exchange for a promise of employment when his studies were complete. Barnhart graduated in 1930 and further undertook graduate studies from 1934-1937.

Noted child psychologist Edward Thorndike approached Scott Foresman with his ideas for a children's dictionary based on his Teacher's Word Book and upcoming Teacher's Word Book of the Twenty Thousand Words Found Most Frequently and Widely in General Reading for Children and Young People The Scott Foresman editors brought Barnhart in to explain Thorndike's proposal after which the project was approved. Together Thorndike and Barnhart co-created the Thorndike-Century Junior Dictionary in 1935 followed by the Thorndike-Century Senior Dictionary in 1941. A revised edition of the Junior Dictionary came out in 1942, followed by the Thorndike-Century Beginning Dictionary in 1945. During World War II the United States Army approached the Linguistic Society of America seeking assistance to write a dictionary of military terms. Barnhart and Jess Stein were sent to New York and undertook the editing of the Dictionary of U. S. Army Terms for the War Department in 1944. Following The American College Dictionary published in 1947, Barnhart contracted with Scott, Foresman to produce the Thorndike-Barnhart dictionary series.

Barnhart's other projects included The New Century Cyclopedia of Names, Century Handbook of English Literature, three dictionaries of new words. He spent the last twenty years of his life working on The Barnhart Dictionary Companion—a quarterly devoted to new words. While in New York, Barnhart found out that Random House had plans to produce an “Americanized” version of the Oxford Concise Dictionary. Random House had acquired the rights to the Century Dictionary and Cyclopedia in the late 1930s and the Dictionary of American English in the early 1940s. Barnhart approached Random House and convinced them to let him take complete control of the project, from concept to design to implementation; this resulted in the American College Dictionary, published in 1947. This work was used as the basis of the Random House Dictionary. While at Random House he produced the New Century Cyclopedia of Names in 1954, a three volume expansion of the original 1894 volume of the Century Dictionary and Cyclopedia.

From the New Century Cyclopedia of Names he further produced the New Century Handbook of English Literature. In the 1950s and 1960s he developed the linguistic approach to reading instruction begun by Leonard Bloomfield, entitled Let's Read, published in 1961. Following the death of Thorndike in 1949, aided by his sons, further updated and revised the Thorndike-Barnhart school dictionaries throughout the 1960s, 1970s and 1980s; these became the most popular school dictionaries in the United States. All dictionaries for schools were published in the trade market by Doubleday. During the 1980s the dictionaries were published under two alternative titles; the advanced dictionary was published as either Thorndike-Barnhart Advanced Dictionary or Thorndike-Barnhart Student's Dictionary. The middle dictionary was published as either Thorndike-Barnhart Intermediate Dictionary or Thorndike-Barnhart Advanced Junior Dictionary; the junior dictionary was published as either Thorndike-Barnhart Beginning Dictionary or Thorndike-Barnhart Junior Dictionary.

In 1997 Scott Foresman was acquired by Pearson Education who retired the work in favour of their Longman brand dictionaries. His largest general dictionary was the World Book Dictionary, a two-volume work created as a supplement to the World Book Encyclopedia, it is an expanded and more advanced version of the Thorndike-Barnhart school dictionaries. It was first published in 1963 and was updated annually until 1976, whereupon it had a major revision, totaling 225,000 individual entries. Consistent with the encyclopedia's use by young people, Barnhart wrote definitions which were both simple and accurate, most entries include sample sentences or phrases. Many definitions are the same, or the same, as those of the Thorndike-Barnhart school dictionaries. Like Webster's Third New International, it included few proper names, leaving them to be covered by the companion volumes of the encyclopedia. Throughout the 1980s up until the 1990s the work was periodically revised and updated with the last revision done by his son Robert and his wife Cynthia Barnhart in 1996.

He co-edited of The Barnhart Dictionary of New English Since 1963, The Second Barnhart Dictionary of New English, The Third Barnhart Dictionary of New English. These works were designed to cover new words and changes in usage. In 1982, with his son David, he began editing a quarterly publication devoted to thorough dictionary treatment of new words, new meanings and changes in usage entitled The Barnhart Dictionary Compan

The Molidae comprise the family of the molas or ocean sunfishes, unusual fish whose bodies come to an end just behind the dorsal and anal fins, giving them a "half-fish" appearance. They are the largest of the ray-finned bony fish, with the ocean sunfish Mola mola and southern sunfish, Mola alexandrini, both recorded at up to 4.6 m in length and 2,300 kg in weight. Molidae have the fewest vertebrae of any fish, with only 16 in Mola mola, they completely lack all caudal bones, most of their skeletons are made of cartilage. No bony plates occur in the skin, which is, however and dense like cartilage and is rough, they lack swim bladders. Molids swim by using their anal and dorsal fins. To steer, they squirt a strong jet of water out of their gills, they can make minor adjustments in the orientation of the anal fin or the dorsal fin so as to control the amount of force it produces and the angle at which the force is produced. In this respect, they use. Molids are said to be able to produce sound by grinding their pharyngeal teeth, which are long and claw-like.

Typical of a member of Tetraodontiformes, their teeth are fused into a beak-like structure, making it impossible for them to close their mouths. Despite this, they feed on soft-bodied animals, such as jellyfish and salps, although they take small fish or crustaceans. Molids have been filmed interacting with other species. Since molids are susceptible to skin parasites, they make use of cleaner fish. A molid in need of cleaning will locate a patch of floating algae or flotsam, home to halfmoons; the molid signals a readiness for cleaning by swimming vertically with its head near the surface of the water, waits for the smaller cleaner fish to feed on the parasite worms. The molid may break the surface of the water with its dorsal fin and beak to attract the attention of a gull or similar seabird; the seabird will dig worms and other stubborn parasites out of the molid's skin. The known fossil history of this genus extends back to the Eocene with the genus Eomola containing the species E. bimaxillaria Tyler and Bannikov, 1992 known from the Upper Eocene of the North Caucasus.

The fossil genus Austromola containing one species, A. angerhoferi Gregorova, Harzhauser & Kroh, 2009, is known from the Lower Miocene Ebelsberg Formation near Pucking, Austria. This species was a resident of the Paratethys Sea and is estimated to have reached a length around 320 cm. At least one fossil species of Mola, M. pileata, is known from the Upper and Middle Miocene of Europe with a possible second species known from the Lower Miocene of North Carolina, United States. The genus Ranzania has five known fossil species: R. grahami Weems, 1985 and R. tenneyorum Weems, 1985, both from the Middle Miocene Calvert Formation of Virginia, USA. Only five extant species in three extant genera are described: Ocean sunfish Southern ocean sunfish, has been recognized as a senior synonym of Mola ramsayi, the "bump-head sunfish" Hoodwinker sunfish Slender sunfish Sharptail mola