14 SlLtTRTD.E. 



The species may be subdivided thus : — 



A. Caudal free. 



* The occipital process is prominent, and angular behind : African 

 and Syrian species, p. 14. 



** The occipital process is not very prominent, and rounded behind : 

 East Indian species, p. 17. 



B. Vertical fins united, p. 20. 



A. Caudal free. 

 * The occipital process is prominent, and angular behind. 



1. Clarias anguiUaris. 



Silurus anguillaris, Linn, in Hasselq. Iteise Palcest. p. 415, and Si/st. 



Nat. i. p. 502. 

 Karmouth, Sonnini, Toy. ii. p. 289. pi. 22. fig. 2. 

 Heterobranchus anguillaris, Geoffr. St.-Hil. Descrijjt. Eg. Poiss. pi. 16. 



fig. 1, cop. with some slight alterations in Cuv. Regne Anim. III. 



pi. 101. fig. 2. 



D. 69-73. A. 53-55. P. 1/9. 



Vomerine teeth villiform, forming a band, which in its middle is 

 narrower than that of the intermaxillaries ; it has not a process be- 

 hind in the middle of its concavity. Head densely granulated above, 

 its length being one-fourth, or rather more than one-fourth, of the 

 total. Barbels slender : those of the nostril two-fifths or one-third 

 as long as, and those of the maxillaries rather shorter than, the 

 head. The pectoral fin extends to, or nearly to, the vertical from the 

 origin of the dorsal ; its spine is short, two-thirds as long as the fin. 



Nile ; West Africa. 



a-b, c. Fourteen to eighteen inches long. Upper Nile. From Consul 



Petherick's Collection. 

 (I. Adult. West Africa. Purchased of Mr. Dalton. 



Hasselquist very distinctly describes the band of vomerine teeth 

 as narrower than that of the intermaxillaries. 



2. Clarias gariepinus. 



Silurus (Heterobranchus) gariepinus, Burcheli, Travels in the Interior 



of South Africa, i. p. 425, c. fig. p. 445. 

 ? Clarias capensis, Cuv. 8f Val. xv. p. 377. 



Clarias capensis, Smith, Ittustr. Zool. S. Afr. Fish. c. tab. (not good). 

 ? Clarias mossambicus, Peters, Monatsber. Berl. Acad. 1852, p. 682. 



(D. 60.) 



D. 66-69. A. 52-54. P. 1/10. 



Vomerine teeth villiform, forming a long, continuous crescentic 

 band, which in its middle is as wide as that of the intermaxillaries, 

 and which has not a process behind in the middle of its concavity. 

 Head densely granulated above, covered with smooth soft Skin in 

 fresh specimens, its length being rather more than one-fourth of the 

 total. Barbels of moderate length, those of the nostrils being one- 



