266 J. G. DE Man: Caridina iiilotica. [Vol. II, 



the typical form of Car. nilotica of Egypt by the slenderer dactyli 

 of the three posterior legs and by the much smaller eggs ; it presents 

 a greater resemblance to the var. gracilipes, de M.^ from Celebes. 



The examination of 6i specimens^ mostl}^ adult or egg-bearing, 

 from Port Canning, proved the following : The usual number of 

 teeth in the proximal series of the upper margin, varies between 20 and 

 24 ; in ten specimens 24 teeth were observed, in nine 23, in nine 

 22, in ten 21 and in eight 20 ; in two specimens the proximal row 

 consisted of 25 teeth, in three of 26, in three of 27, in one of 29 ; 

 in only two individuals were 19 teeth and in only one (very young) 

 specimen were 17 teeth observed. The rostrum usuall}^ extends 

 slightly beyond the antennal scales, or it appears just as long, 

 rarely is it a little shorter. In all the specimens the proximal row 

 of teeth appears considerably longer than the terminal unarmed 

 part and the proportion between the length of the latter and that 

 of the proximal row of teeth is as i : 2 — 4*5. Whereas in the adult 

 ova-bearing female (No. i of Table F) 28 mm, in length, the proximal 

 row of teeth is only twice as long as the terminal unarmed part, it is 

 4 or 5 times as long in a quite young specimen (No. 15) I2"5 mm. in 

 length, and, as is shown by the Table, the other specimens present 

 all possible intermediate proportions. Usually two teeth are 

 placed on the carapace, often, however, three and in one speci- 

 men four teeth are placed on the carapace. One observes one sub- 

 apical tooth as often as two ; of the 61 specimens 24 carried one 

 sub apical tooth, in 31 two subapical teeth were found, in 2 three 

 and in i specimen even four (compare the toothing-formulae). 

 In some specimens one or two isolated teeth occur on the unarmed 

 terminal part of the upper edge between the proximal row and 

 the subapical tooth : of the 61 examined specimens, 13 presented 

 one isolated tooth and in one case two existed. The usual number 

 of teeth on the lower margin varies between 11 and 14 : of the 61 

 specimens in sixteen the lower margin was armed with 11 teeth, 

 in eleven with 12, in eight with 13, in ten with 14, in two with 15, 

 in two with 16, in one with 17, in five with 10, in three with 8 and 

 in one with 6. One of the specimens in which the lower margin is 

 armed with 8 teeth and also that with 6 are adult ova-bearing 

 females. 



The largest specimen from Dhappa (26*5 mm. long) differs 

 a little from the preceding. The rostrum projects with one- third 

 of its length beyond the antennal scales, i.e., farther than in the Port 



21^ -H I 

 Canning specimens ; it is dentate and the two foremost 



13 

 teeth of the upper margin are farther distant from each other than 

 the rest. In this specimen the proximal row of teeth is but i"8 

 times as long as the terminal unarmed part. 



In Table F the toothing-formulse of 16 specimens are indicated ; 

 the formula — 



■ . 17^ + I + I 



