54 On a new African Fish. 



VI. — Description of a new African Fish of the Qenus 

 Cl&nas from Lake Rukwa. By G. A. Boulenger, F.R.S. 



(Published by permission of the Trustees of the British Museum.) 



Little is known of the fishes of Lake Rukwa, south-east 

 of Lake Tanganyika. Twelve species liave been enumerated 

 by Hilo;endorf and Pappeiiheitn (Sitzb. Ges. naturf. Fr. 

 Berl. 1903, p. 259), the determinations of some of wliicli 

 appear to be in need of revision. On the occasion of a recent 

 visit Mr. F. n. Mcllard has been so good as to preserve a few 

 fish for the British Museum ; among these I may notice 

 Amphilius platychir, Gthr., Glorias gariepinus, Burch., and a 

 new Clarias which I propose to name, in memory of the late 

 Prof. Franz Hilgendorf, 



Clarias hilgendorji. 



Depth of body 6^ times in total lengtl), length of head 4§ 

 times. Head 1? times as long as broad, smooth ; occipital 

 process longer tiian broad, acutely pointed ; frontal fontanelle 

 sole-shaped, 2^ times as long as broad ; occipital fontanelle 

 narrow, elongate, partly on occipital process; eye very small, 

 3 times in length of snout, 6 times in interorbital widtii, 

 which is a little less than \ length of head ; band of pvaj- 

 maxiUary teeth not quite 4 times as long as broad ; vomerine 

 teeth granular, forming a curved band which is nearly as 

 broad as the prjemaxillary band ; nasal barbel | length of 

 head, maxillary 1^, outer mandibular nearly 1, inner man- 

 dibular |. Gill-rakers few, 12 on first arch. Clavicles 

 concealed under the skin. Dorsal 73, its distance from 

 occipital process \ length of head. Anal 62. Dorsal and 

 anal extending almost to the very root of the caudal. Pectoral 

 not quite \ length of head, spine short, strongly serrated on 

 both sides. Ventrals very small, Ig times as far from caudal 

 as from end of snout. Caudal \ length of head. Uniform 

 blackish brown ; caudal with a narrow light edge. 



Total length 130 mm. 



A single specimen. 



Allied to CI. laviceps, Gill. Distinguished by the granular 

 vomerine teeth, fewer gill-rakers, fewer dorsal aud anal rays, 

 and a longer aud narrower occipital process. 



