418 BULLEPIN UNITED STATES GEOLOGICAL SURVEY, 



26.— *QuASSiLABiA Jordan & Brayton. 1878. Hare- lip Suckers. 



(Lagochila J. & B., 1877, preoccupied.) 



104. Quassilahia lacera Jordan & Brayton. Tennessee River. 



CYPEINID^. 

 27. — ExoGLOssuM Eafinesque. 1818. Cat-lips. 



105. Exoglossum maxillilingua (Raf.) Haldeman. New York to Ohio and 



Maryland. 



28. — Campostoma Agassiz. 1855. Stone Rollers. 



106. Campostoma anomalum (Raf.) Ag. Ohio to Dakota and Sooth. 



107. Campost07na formosuhim Grd. Texas, {d. s.) 



108. Campostoma nasutum Grd. New Leon. {d. s.) 



109. Campostoma ornatum Grd. Chihuahua River, {d. s.) 



29. — ACROCHILUS Agassiz. 1855. Hard- mouth Chubs. 



110. Acrochilus alutaceus Ag. & Pick. Columbia Basin. 



30. — Orthodon Girard. 1856. 



111. Orthodon microlepidotus (Ayres) Girard. California; Utah. 



31. — Hybognathus Agassiz. 1855. Blunt-jawed Dace. 

 § Hybognathus. 



112. Hybognathus placitus Grd. Arkansas River. 



113. Hybognathus nuchalis Agassiz. Ohio Valley to New Mexico. 



114. Hybognathus argyritis Girard. New Jersey to Dakota, New Mexico, 



and south. 



115. Hybognathus regius Girard. Chesapeake Basin. 



116. Hybognathus evansi Grd. Nebraska, [d. s.) 



117. Hybognathus siderius Cope. Arizona. 



118. Hybognathus Jlavipinnis Cope, M.SS. Texas. 



119. Hybognathus nigrotceniattis Cope, MSS. Texas. 



* Wheu the name Lagochila was first proposed for this genus, its authors were not 

 aware that the masculine form, Lagochilus, had been already given to two different 

 genera, to one of Gasteropods by Blanford, and to one of Insects by Loew. The words 

 Lagochila and Lagochilus are identical in etymology and in all except terminations, 

 and many writers would consider them insufficiently distinct, and would hold that 

 the name Lagochila should be changed. At present, I am inclined to the contrary 

 opinion ; nevertheless, as the matter stands, and as the name Lagochila has not yet 

 come into general use, less confusion perhaps will result from renaming the genus, 

 than from any other course. The name QuassilaMa (Jordan & Brayton) is accordingly 

 suggested as a substitute for Lagochila, considered to be preoccupied in conchology. 

 The etymology is quassus, broken or torn ; laUa, lip. The case is precisely like that 

 of the genus of Doves, Leptoptila Swainson, lately named ^cAwiopttZa by Dr. Coues, on 

 account of the previous Leptoptilus of Lesson. 



