XXII. NOTES ON CRUSTACEA DEC A POD A 

 IN THE INDIAN MUSEUM. 



XII. SCOPIMERINAE. 



By Stanley Kemp, B. A., Supcrintoident , Zoological Survey 



of India. 



Plates XII, XIII. 



This subfamilv of Ocypodidae comprises a number of very 

 small crabs found on the sea shore or in estuaries and backwaters. 

 Eour genera have hitherto been recognised : — Scopimera, de Haan^ 

 Dotilla, vStimpson (= Doto, de Haan), //yo />/(7 a;, Stimpson and Tym- 

 panomerus , Rathbun (= Dioxippc, de Man). A fifth is here desctibed 

 under the name Dotillopsis. 



The range of the subfamil}' extends from the southern and 

 western coasts of Africa and the Retl Sea to the Banda Sea, the 

 Philippine Is. and Japan. Its headquarters appear to be on the 

 Indian coasts on which all tlie genera except th^ problematical 

 Ilyoplax occur. 



Including the new forms here described thirty species of 

 Scopimciiiae are now known: of these I have seen twent^^-one. 

 Eighteen species are known from the Indian coasts and of these I 

 have seen all but one and the types or paratypes of thirteen. 



The Scopimerine crabs are of small size as compared with the 

 Oc3'podinae. They are all littoral or estuarine and strictly amphi- 

 bious in habits. Unlike Ocypoda the coastal species live only in 

 sheltered bays o\\ the shores of which surf never breaks. The 

 species of Dotilla and Scopimcra burrow in damp sand between 

 tide-marks and different forms are as a rule restricted to different 

 levels on the beach. For example, both in Mormugao Bay on the 

 west coast of India and at Tuticorin on the south-east coast Scop- 

 iniera proxima and Dotilla myctiroides occur, the former inhabiting 

 the zone near high-water mark, while the latter is to be found near 

 low-water mark. Tympanonierus burrows in rather stiff clay ,or 

 muddy sand, while Dotillopsis affects estuarine mud of ths/ softest 

 consistency. 



All the species construct small oblique burrows, from 'which 

 they remove the sand or mud in little pellets. This is done as 

 often as the tide sinks and exposes the area in which they are 

 living. In nearly all cases the pellets are disposed with some care, 

 in such a way that one or more pathways are left clear on the 

 surface round the mouth of the burrow. The path wa\'s themselves 

 are smoothed and apparently hollowed out by the crab. The 



