FAMILY, V-CYPRINID^. 625 



The existence, number or absence of barbels has been considered by some antbors to be a reason for 

 constituting genera, but such is not_ generally held to be valid. These appendages, more especially when the 

 fish are not kept in a state of domestication, or confinement, but left in natural situations, appear to be pretty 

 constant, and though not in themselves cause enough for defining a Genus, are frequently sufficiently well 

 marked for the purpose of forming sub-genera, good examples of which may be seen in the Genus Barbus, or 

 Ba/rilms. On the other hand, in some species these appendages may be abnormally absent, as in the Danio, 

 consequently sub-divisions of the Genus founded solely on this character would lead to erroneous results. 



The position of the fins indicate sub-divisions which may be used in the primary groups, and have for 

 convenience sake been adopted as follows : — 



a. Dorsal fin commencvng nearly opposite the ventrals, the anal being short. 



b. Dorsal fin commencing very distvncthj posterior to the ventrals, but not extending to above the anal, which 

 last is short, or of moderate length. 



e. Dorsal fin commencing in the interspace between the ventral and anal, or over the latter, and generally 

 extending to above it : whilst the anal is of moderate length or elongated. 



The character of the dorsal fin is likewise important, but its length alone, or rather the number of its rays, 

 appears insufficient for the purpose of defining a Genus, much less a sub-division of a group. When an uninter- 

 rupted series extends from a few rays to a large number, and no other sufficient difference exists, such divisions 

 cannot be considered natural ones : and if artificial, they can never form the basis of a scientific classification. 



The last undivided dorsal ray is variously formed, being articulated or osseous, which latter 

 may be smooth or denticulated, but all these varieties may be found in a single Genus, as Barbus. The anal fin 

 sometimes shows peculiarities, as ia the Barbus apogon, C. and V., where the undivided rays are spinate. 



Scales, simply as regards their size, unless conjoined to other characteristics, cannot by themselves be 

 taken as a reason for making Genera, because large, moderate, and small-sized scales are all occasionally found 

 represented iu a single Genus. But certain modifications may exist, as in the mountain barbels, 

 Schizothoraeince, where a row of tiled scales encloses the excretory outlets and base of the anal fin ; or portions 

 of the body may be naturally left scaleless. 



The lateral-line has been employed as one of the signs for the formation of groups, according to its 

 position, as along the middle of the side, or near the abdominal edge ; a plan I have not adopted, because its 

 complete existence in some species seems of but little importance : thus in the Genera Barbus, or Barilius, it 

 may be present, or partially absent, sometimes ceasing after proceeding along a very few rows of scales. 



As to the internal characters, the skeleton forms one of the most important features, respecting which 

 much still remains to be investigated in the Indian carps, and the same remarks apply to the internal organs. 



The pharyngeal teeth are in from one to three series, but these numbers alone do not always suffice for the 

 definition of even Genera : thus in the Chelas some have them in two and others in three rows. Even the form 

 of those teeth is not invariably similar in all the species of the same Genus : thus in the Bohtee microlepis, Blyth, 

 • these teeth have serrations on their edges, and the two largest of the anterior row are molariform, whereas 

 crooked and pointed ones are the rule in the Genus. Likewise the teeth are deciduous, being constantly shed 

 and replaced : they may become blunted with age, although they had at first been sharp and pointed. 



I have not retained the sub-family, Homaloptervna, or carps destitute of an air-vessel, because 

 PsilorhynchMS links it very naturally with Disaognathus. In short most of the distinctive characters consist of 

 possessing a single row of pharyngeal teeth and the absence of the air-vessel. In many fishes these however 

 are deemed insufficient on which even to characterize genera. Homaloptera leads very naturally from some of 

 the mountain siluroids to the true carps on one hand, and to the Loaches on the other. 



p, d"f s 



A. Abdomen rounded, not trenchant. ' 



A: — Dorsal fin commencvng nearly opposite the ventrals. Anal short (5 to 7 branched rays.) f 



Genus, 1 — HoMALOPTEEA, V. Hasselt. 



Balitora, Gray : Platycara, McClelland. 



Head and anterior part of body depressed : snout more or less spatulate. Mouth small, inferior, with two 

 paWs of rostral barbels, and one at either angle of the mouth. Pharyngeal teeth small, from 5 to 16 in one row. 

 Pectoral and ventral fins with many rays, the outer of which OA-e simple. Dorsal short, situated . opposite to the 

 ventrals : anal likewise short. 



Geographical distribution. — Through some of the hilly districts of the Himalayas to the Wynaad and 

 Bowany river in the Madras Presidency : also found in the fresh waters of Java and Sumatra. 



SYNOPSIS OP SPECIES. 



1. Homaloptera Brucei, D. 3/8, A. 2/5, L. 1. 70. Lower caudal lobe the longer. Brown blotched with 

 a darker tinge. Himalayas and South India. 



