152 On a new Ciclil id Fish from Lake Tanqanyika. 



XX. — A new Ciohlid Fish of the Oenus Limiiochroinis 

 from Lake Tanganyika. By C. Tate Regan, M.A., F.ll.S. 



(Piiblidbed by permissiou of tbe Trustees of tbe Britisb Museum.) 



Limnochromis otostigma, sp. n. 



Pelmatochromis auritus (part.), Bouleng. Cat. Afr. Fisb. iii. p. 415 

 (lyio). 



Depth of body 3 to 3^ in the lencrth, length of head 3 to 3J. 

 Snout as long as or shorter than diameter of eye, which is 3 

 to 3^ in length of head, greater than prteorbital depth ; inter- 

 orintal width 4 to 4^ in length of Lead. Jaws equal ante- 

 riorly ; niaxillav}' ext'-nding nearly to below middle of eye; 

 teeth small, in 2 or 3 series. 4 or series of scales on cheek. 

 11 or 12 gill-rakers on lower part of anterior arcii. A more 

 or less distinct papillose ))ad on each side in front of the 

 upper pharyngeals. Lower pharyngeal a triangular plate 

 with doubly convex posterior edge and with a long anterior 

 blade; teeth all slender. Dorsal XV (XVI) 9-10; last 

 sj)ine }, length of head. Anal 111 8-9. Pectoral as long as 

 head, extending to origin of anal. Caudal rounded. Caudal 

 ])eduncle 1.'^ as long as deep. 35 or 36 scales in a longitu- 

 dinal series, 5 or 6 from first dorsal spine to lateral line. 

 Olive-brown, with oblique cross-bars of .silvery white ; a 

 blue-black opercular spot; fins greyish. 



Lake Tanganyika. 



Seven s])ecimeu3, measuringup to 100 mm. in total length. 



Z/. auritus is often a little deeper (depth 2^ to 3 in the 

 length) and has the mouth a little smaller (maxillary to below 

 anterior ^ of eye), and the spinous dorsal, with IG or 17 spines, 

 a little lower ; also the silvory-white cros.s-bars on the body 

 are absent, but the vertical iins have ])ale si)ots and dark 

 stripes. The most notable external dill'crenco between the 

 two species is in the form of the cauilal fin, rounded in 

 /,. otostigma and eniarginate in L. auritus ; this is not due to 

 age, but is evident when examples of the same size are com- 

 ])ared. Another important difference is that in L. auritus 

 the lower pharyngeal has no distinct anterior blaile and that 

 a few teeth in the middle near its j)osterior edge are rather 

 stout and blunt. 



