48 Annals of the South African Museum. 



when a Bopyrid is lodged in the cheek-piece of a prawn, seems 

 far less natural when its residence is between the pleopods, 

 unless inherited from an ancestry differently located. Cryptione 

 elongatus, Hansen, was described in 1897 from the branchial 

 cavity of Nematocarcinus agassizii, Faxon, and quite recently 

 Mr. K. H. Barnard has described Zonophryxns quinquedens, 

 n. sp., found in company with an unnamed South African 

 species of Nematocarcinus. 



FAMILY ATYIDAE. 

 1879. Atyidae, Kingsley, Pr. Ac. Sci. Philad., p. 414. 



GEN. CAEIDINA, Milne-Edwards. 



1837. Caridina, Milne-Edwards, Hist. Nat. Crust., vol. 2, p. 362. 

 1910. Stebbing, Ann. S. African Mus., vol. 6, pt. 4, p. 393 



(with synonymy). 



1912. Lenz, Arkiv for Zoologi, vol. 7, No. 29, p. 4. 



1913. ,, Bouvier, Tr. Linn. Soc. London, Ser. 2 Zool., vol. 15, 



pt. 4, p. 447. 



CAKIDINA NILOTICUS (Eoux). 



1833. Pelias niloticus, Eoux, Ann. Sci. Nat., vol. 28, p. 73, pi. 7. 



1908. Caridina nilotica, de Man, Eecords Indian Mus., vol. 2, 



pp. 255, 262, 263. 



1910. ,, ,, Stebbing, Ann. S. African Mus., vol. 6, 



pt. 4, p. 394. 



To judge by the elaborate researches of Dr. de Man and 

 Professor Bouvier the species of Caridina are capable of yield- 

 ing an endless number of variations. Professor Bouvier has 

 patiently dealt with hundreds, nay, thousands, of specimens. 

 With seven specimens at my disposal from a single locality, 

 it may be interesting to give details as to the rostrum in each. 

 The first examined excited attention by a feature which did 

 not recur in any of the others, namely, by having three dorsal 

 teeth lying closely in succession behind the apex ; they were 

 separated by a long smooth interval from the series of 17 

 dorsal teeth, of which 2 are behind the orbit; 10 ventral teeth 

 form a series beginning some way in front of the eyes and 

 ending in advance of the dorsal row but at some distance from 



