10 SII/URIDiE. 



Fifth Subfamily. 



SILURID^ STENOBRANCHm 



Dorsal fin short, if present, before the ventrals (except in 

 Khinoglanis) ; gill-membranes confluent with the skin of the 

 isthmus. 



Group K. Doradina. 



Rayed dorsal fin present. The anterior and posterior nostrils are 

 remote from each other. 



a. Adipose fin exceedingly small or absent ; lateral line without bony shields : 



South American. 



* The cleft of the mouth extends to, or to below, the eye. 



Adipose fin present ; barbels two 72. Agexiosus, p. 191. 



Adipose fin present ; barbels four, very small. 73. Tetranematichthys, p. 192. 



Adipose fin present ; barbels six, the four mandibulary barbels being placed in a 

 transverse series immediately behind the symphysis. 



74\ Euanemus, p. 193. 



Adipose fin present ; anal longish ; barbels six : a maxillary, an anterior and a 

 posterior mandibulary pair 75. Auchemptf.rus, p. 194. 



Adipose fin present ; anal short ; barbels six. 76. Centrojiochlus, p. 197. 



Adipose fin none; head osseous above 77. Traciielyoi'tekus, p. 198. 



Adipose fin none ; head covered with thick skin. 



78. Cetopsis, p. 199. 



** Cleft of the mouth very wide, extending far behind the eye. 

 Adipose fin present 79. Astrophysus, p. 200. 



b. Lateral line armed with bony shields : South American. 



Adipose fin short, very distinct ; teeth villiform ; barbels not fringed. 



80. Doras, p. 200. 



Adipose fin short, very distinct ; teeth rudimentary ; barbels fringed. 



81. Oxydoras, p. 206. 



Adipose fin low, longish 82. Rhixodoras, p. 209. 



c. Adipose fin of moderate length ; lateral line without bony shields : African. 

 The lower jaw with moveable teeth 83. Synodontis, p. 210. 



Group L. Rhinoglanina. 

 The anterior and posterior nostrils are close together. 



Adipose fin replaced by a rayed fin ■ neck with broad shields. 



84. RlHNOGLANtS, p. 216. 



Adipose fin replaced by a rayed fin ; neck covered with skin. 



85. MocHOCua, p. 217. 



A nasal barbel 86. Callomystax. p. 218. 



Group M. Malapterurina. 



No rayed dorsal fin. Africa. 

 Adipose fin of moderate length 87. Malapterurus, p. 21 l J. 



