428 CEYLON PEARL OYSTER REPORT. 



the other hand, the character of the marginal teeth of the carapace, the male cheliped 

 measurements and the size of the crab (measured by C.I.), are correlated. 



The cheliped differences in the males have the appearance of being growth -changes. 

 The appearance of regenerated cheliped of (B) is suggestive (PI. II., fig. 3, b). Possibly 

 the differences in the character of the marginal teeth are also growth-changes ; one 



C_^1IV:2 PP"^ r "2^B C. 



Fig. 12. Monophthalmus latreillei growth stages of male chela. 



requires more evidence. It may be noted that in all the males the copulatory 

 appendages appear to be well developed ; it would be difficult to say that the smaller 

 specimens are not sexually mature. 



I have seen Miers' small "Challenger" specimens from Japan, referred to by 

 Ortmann, and put them with the example in the present collection. In one of them 

 the degree of development of hair on the carapace is much as in my specimen. 

 Specimens of this variable species are often found as sub-fossils (Henderson, p. 389). 



Elamena truncata, A. M.-Ernv., 1873 A.6, p. 386. 



Locality : Galle Bay, " From bags hung from buoy," three specimens. 



Description : (it) young ? . (6) young ? . (c) adult ? . 



C.l 5-00 5-25 6-25 



C.b.-=-C.l 0-95 0-95 1-00 



The front is " broadly truncated," but its anterior border cannot be described as 

 "quite straight." Borradaile (B.X., p. 682) follows Ortmann in placing the 

 Hymenosomidse among the Oxyrhyncha. 



Geograpsus crinipes (Dana, 1851) A.6, p. 396. 



Locality : Galle, in tow-net, one specimen. 



Description: An adult male, C.l. = 32 '00. The label gives colours in life: 

 " Dorsum of carapace very dark purplish -red, ventral surface red (except dactylo- 



