NATURAL SCIENCES OF PHILADELPHIA. i 



to be entitled to family rank. The chief and typical family is much the most 

 extensive and widely distributed. The others are small and much more re- 

 stricted in geographical distribution. 



The following synopsis will exhibit the most obvious characteristics of the 

 different families, and their geographical distribution. We do not pretend 

 to group the various genera into subfamilies or tribes, where so many have 

 failed ; it would be presumptuous for us, with the material at hand, to offer 

 such an arrangement. 



Family I. HOMALOPTEROIDiE Gill. 



Synonymy. 



Homalopterseformes Bleeker, Natuurkundig Tijdschrift voor Nederlandsch Indie, 



vol. xx. p. 422 (subfamily.) 

 Balitora Cuv. et Vol. Hist. Nat. des Poissons, vol. xviii. p. 91, (genus.) 



The body and head are depressed, and the inferior surface plane. The 

 mouth is inferior and of small size. The pectoral and ventral fins are in the 

 same plane, horizontal and subdisciform. The pectoral fins have numerous 

 and branched rays. There are no spines before any of the fins. The pharyngeal 

 bones have a single row of conical teeth. 



This family exactly corresponds to the subfamily of Homalopterasformes of 

 Dr. Bleeker, and the characters above given are nearly translated from his. 

 The species are peculiar to the streams of India. 



Family II. COBITOIDJE Fitzinger. 



Cobitidse Fitzinger. 



Acanthopsides Heeled and Kner, Die Slisswasserfischedes Ostreichischen monar- 

 chic, p. 296. 

 Cobitiformes Bleeker, Natuurkundig Tijdschrift voor Nederlandsch Iudie, vol. 

 xx. p. 421. 



The body and head are never depressed, but either subcylindrical or slightly 

 compressed. The scales are very small, and almost concealed in the smooth 

 mucous skin. The mouth is subterminal, the snout being little protuberant. 

 The lips are thick, and provided with from six to twelve barbels. The pecto- 

 ral fins have a broad, vertical base, and are inserted in the usual manner on 

 the sides above the breast. The pectoral fins have each a simple spine ; the 

 others are without. The pharyngeal bones have a single row of teeth. Th* 

 branchial apertures are small and restricted to the sides. 



This family is confined to the fresh-water streams and lakes of Europe and 

 Asia, both temperate and tropical, and the islands of the Sunda Molluccan Ar- 

 chipelago. No species are found in either of the Americas. Are they not re- 

 placed in the latter continents by the fresh water Siluroids and Triehomyete- 

 roids ? 



The family may be divided in two different subfamilies, distinguished by the 

 position of the dorsal fin. In the typical Cobitince, that fin is placed immedi- 

 ately over the ventral fins. In the other group, which may be called Acanthopk- 

 thalmincE, the dorsal is situated over the space between the ventral and anal 

 fins. Of the former four genera are known, and of the latter two. 



Family III. CYPRINOIDiE (Cuv.) Gill. 



Synonymy. 



Cyprinida? partim Agassiz, auct. 



Cypriniformes Bleeker, Natuurkundig Tijdschrift voor Nederlandsh Indie, vol. 

 xx. p. 422 (subfamily.) 



1861.] 



