igig- 



vS. Kemp : Notes on Crustacea Decapoda. 



325 



Forskal. D. clepsydrodactylus, iVlcock, appears to me to be nothing 

 more than a fully developed form of D. intermedia, de Man, 

 while Stebbing's D. clepsydra does not seem to be distinguishable 

 from Hilgendorf's D. fenestrata. 



The mutual affinities of the species are best understood by a 

 stud}^ of the grooves of the carapace. In text- fig. q will be found 

 illustrations of the carapace of six species, the figures represent- 

 ing all the known types of sculpture. Two species I have not 

 seen, — D. fenestrata, in which the sculpture is almost identical 

 with that of D. sulcata, and D. milaharica, which in this respect 

 bears a close resemblance to D. pertinax. 



Text-fig. 9. — Carapace sculpture in Dotilla. 

 D. myctiroides (Milne-Edwards). d. D. wichmanni, de Man. 



D. sulcata (Forsk§,l). e. D. blanfordi, Alcock. 



D. pertinax, Kemp. /. D. intermedia, de Man. 



The Species are often difficult to determine, partly owing to 

 the fact that the grooves of the carapace are not easy to observe 

 and partly because samples from a particular locality frequently 

 consist only of comparatively small individuals, to the exclusion 

 of large males with well developed secondary sexual characters. 

 I have already remarked (p. 306) that the absence of full 

 grown males is, in certain cases at any rate, to be attributed to 

 an unfavourable environment. Males of D. intermedia are subject 

 to a well-marked dimorphism. 



With the exception of D. fenestrata all the known species of 

 Dotitla have been found on the Indian coast. They may be dis- 

 tinguished thus : — 



