Invertebrate Gallery of the Indian Museum. 79 



1st Family, Galatheidae. The majority of the Gala- 



theidsc inhabit deep water : they are represented 



in the Gallery by specimens of Galathea from a 



moderate depth, and of Munida, Munidopsis 



and Galacantha from the great depths. 



2nd Family, Porcelianidae. ^h& Porcellanidse 2iX%{owx{^ 



hiding under rocks and stones in tidal pools, 



and are very common in India. The members 



of this family have a large abdomen, but it is 



bent up beneath the thorax as in the Crabs. 



The Indian genera represented are Porcellana 



and Petrol isthes. 



In their growth, as already stated, the Macrura Deca- 



poda, like the Stomapoda, usually pass through several 



metamorphoses, the various stages of which differ very 



greatly from the adult form. Some of these larval forms 



are shown in Case 54, e.g., the Mysis stage of the Prawn, 



the Zoaea and Megalopa stage of the Crab, and the 



Phyllosoma stage of the Scyllaridx 2lXs.^ Palinuridse ; and 



in Cases 55 and 57 are series of enlarged drawings. 



Before leaving the Crustacea mention must be made 

 of the genus Nebalia, an example of which is exhibited 

 in Case 54. Nebalia is in some respects intermediate 

 between the Entomostracous and Malacostracous Crusta- 

 cea, since the abdomen has more than seven segments and 

 ends in a caudal fork as in Apits, and since the thoracic 

 limbs are bilobed plates. By Professor Ray Lankester 

 Nebalia is independently graded by itself, between the 

 Entomostraca and Malacostraca, as the sole remaining 

 representative of a third group named by him Leptos- 

 traca. 



APPENDIX TO CRUSTACEA No. I. 

 2. ARTHROPODA PCECILOPODA. 



[§Mc0txrii (!MaU-fa0i^ 56 J. 

 The only living representative of this group, Limulus — 



