Mr. J. McClelland on Indian Cyprinidae. 117 



The lower jaw of the Barbels is composed of two longer 

 limbs (fig. 6, plate 54) articulated behind as in the Cirrhins, 

 but without transverse apophyses in front, where the two 

 bones are united by symphysis, or close union, firmly ce- 

 mented as it were with cartilage. 



In the Gudgeons the chin is rounded horizontally, without 

 the depression in the middle observed in that of the Cirrhins, 

 or the acute lengthened apex of the Barbels, and is composed 

 of a solid bony rim, formed of a transverse process directed 

 from each corner of the mouth to the centre, where it is firmly 

 united to its fellow by symphysis at the chin ; at the corners 

 of the mouth these transverse processes turn backwards at 

 right angles (as in Cyp. bata, Buch., fig. 3, plate 54), and some- 

 times at still greater angles, as in (fig. 2, plate 54) Cyp. mri- 

 gala, Buch. This last process is articulated behind to the 

 anterior process of the preoperculum, and corresponds with 

 Cuvier's angular bone in the Perch. 



42. The angular transverse processes in this last form have 

 every appearance of being two distinct pieces (c and d, fig. 2, 

 plate 54), consolidated in adults by a bony union at the comer 

 of the mouth, yet formed from distinct centres of osseous de- 

 posit. Now as these three forms are each attended with pe- 

 culiar traits of character in regard to the nature of food and 

 the manner of obtaining it, as well as in the structure of their 

 digestive organs, we may be sufficiently justified in regarding 

 them as characterizing three types, which, if we like, we may 

 term primary. This view is further supported by the fact, 

 that to one or other of the three forms in question, variously 

 modified, the lower jaw of all the Cyprins of this country may 

 be referred. In Cyprinus semiplotus (fig. 1, plate 54) the an- 

 gular process is merged into the transverse, the first being 

 only distinguished by the pterygoid process (c, fig. 1, plate 

 54), which we know, from all the other species examined, to 

 belong to the angular limb (d, fig. 2, plate 54), and not to the 

 transverse process on which it is in this species placed ; while 

 the analogy to the type of the Gudgeons is preserved by an 

 additional transverse bone being placed parallel to and in front 

 of the first (e, e, fig. 1 and 2, plate 54). Of the positive value 

 of these characters, I may mention that Cyprinus mrigala, 

 Buch., is indicated by Cuvier as a Cirrhinus, but proved 

 by this method of analysis to belong to the Gudgeons {Gobio 

 prop., J. M.), having, as well as the peculiar affinity here 

 pointed out, the lengthened alimentary canal of that genus. 



Cyprinus prop., Cuvier, I suspect will be found, according 

 to these principles, to agree in its natural affinities either with 

 the Barbels or Cirrhins, as the length of the dorsal and the 



