Invertebrate Gallery of the Indian Museum. 77 



seashore : the abdomen is long and narrow, 



and is tucked up under the thorax, as in crabs. 



2nd Family, Albuneidge — represented by Albunea, 



which much resembles Hippa both in form 



and in habit. 



2nd Tribe, Paguridea, Case 42. — This tribe includes the 



Hermit-crabs, most of which are marine; though several, 



such as Birgiis and many Cenobites, are terrestrial, being 



specially abundant in the dense damp jungles of the 



islands of the various archipelagos of the Indo-Pacific. Of 



•the four families included in this tribe, three — the Pagu- 



ridas, the Cenobitidse^ and the Parapaguridse — are found in 



the Indian region. 



ist Family, Pagurldae — Hermit-crabs or Soldier-crabs. 

 The Hermit-crabs differ from all the higher 

 Crustaceans in having the abdomen not encased 

 in a calcareo-chitinous exoskeleton like the 

 rest of the body, but covered only with a soft 

 skin. For the protection of this soft vulner- 

 able abdomen they possess themselves of a 

 mollusk shell, which they change periodically 

 as they grow in size, and the spiral curvature 

 of which leads to a corresponding partial spiral 

 curve in the abdomen. They are common 

 in tidal pools, and are represented in the 

 Gallery by specimens of Pagurtis, Clibanarius, 

 and Diopencs. 

 2nd Family, Parapaguridse. — The Parapaguridse are 

 a deep-water family, differing from the Pagu- 

 ridde only in the structuie of the gills. They 

 are represented in the collection by specimens 

 of Parapagurus abyssorum, Pylocheles, and 

 Pagurodes. 

 Parapagurus abyssorum is invariably found living 

 commensal with a colony of sea-anemones 

 [Epizoanthus), as is well seen in the beautiful 

 specimen exhibited. Pagurodes also lives com- 

 mensal with a sea-anemone. 



