632 ME. B. A. SMITH ON LAND AND FRESHWATEE [NoV. 7, 



posterior margin ; pectoral fin extending to the origin of the anal. 

 (Scales rough, apparently uniform greenish, with a blackish spot on 

 the end of the operculum ; two narrow blackish bars across the 

 upper surface of the snout ; the soft dorsal with a row of rounded 

 darker spots behind each ray. 

 One specimen. 



Cheomis diaghamma, sp. n. (Plate LVIII. fig. B.) 



17-18 A =^ X 1 i. orv T i. 3i 



D. -rr ■ A. '--. L. lat. 30. L. transv. 



10 ■°" 7' -LI. i«n. wv. -^' "^i '*"=>'• 7 &^ very small ones. 



This species has the upper profile of the head descending in a 

 curve, reminding one of Diagramma. Teeth bicus])id, the inner 

 cusp being the longer and brown ; twenty-eight on each side of 

 the outer series of the upper jaw. Scales below the eye in four 

 series. In a specimen 3| inches long the diameter of the eye equals 

 the \A"idth of the prasorbital and the depth of the scaly portion of 

 the cheek, but is less than the width of the interorbital space, which 

 is convex. The angle formed by the pi-ieopercular limbs is a right 

 one. The height of the body is rather more, and the length of the 

 head less, than one tliird of the total (without caudal). The length 

 of the last dorsal spine is two fifths of that of the head ; caudal 

 scaleless, with vertical posterior margin ; pectoral fin extending to 

 or nearly to the origin of the anal. Scales rough, with minute 

 spines on the margin. The coloration seems to be uniform 

 greenish, in the smaller specimens with indistinct narrow darker 

 cross-bands. 



Three specimens, the largest of which is 3| inches long. 



EXPLANATION OF PLATE LVIII. 



Fig. A. Chromis horei, p. 630. 



B. Chromis diagramma, p. 632. 



C. Chromis hurtowi, p. 631. 



3. On a Collection of Land and Freshwater Shells trans- 

 mitted by Mr. H. H. Johnston, C.B.^ from British 

 Central Africa. By Edgar A. Smith. 



[Received August 28, 1893.] 



(Plate LIX.) 



The specimens comprised in this collection were obtained partly 

 by Mr. !R. Crawshay at Lake Mweru, Lake Tanganyika, and on the 

 northern part of Lake Nyasa, and partly by Mr. A. Whyte at the 

 southern end of the last-mentioned lake. They have been pre- 

 sented to the British Museum by H. H. Johnston, Esq., C.B., 

 H.M. Commissioner in British Central Africa, to whom that insti- 



