62 A Guide to the Zoological Collections in the 



In their growth thsy pass through several metamor- 

 phoses, and even the later larval stages differ so much 

 from the adult that they were originally taken to belong 

 to a different genus, one of which was described as Erich- 

 thus. Several specimens of Squilla in the Erichthus stage 

 are exhibited. 



The Stomapoda are represented by specimens of the 

 following genera : — Squilla, Lysiosquilla, Chloridella, 

 Pseudosquilla, Protosquilla, Gonodactylus. 



V. CRUSTACEA MALACOSTRACA SCHIZOPODA. 

 [ffl;c0U rn md\-t&Qt 54]. 



The Schisopoda have a complete outward resemblance 

 to prawns, but they differ from the prawns and their re- 

 latives in the form of the thoracic limbs, all of which are 

 forked from near the base — hence the name of Schizopoda 

 or cloven-footed Crustaceans. 



The Schizopoda are mostly small, but some of the 

 deep-sea forms are as large as a small prawn. In the 

 exhibited collection they are represented by fine speci- 

 mens of Gnathophausia and Eucopia from the depths of 

 the Bay of Bengal. 



In Gnathophausia the external structure of the Schizo- 

 pod body can be very well seen. 



vi. CRUSTACEA MALACOSTRACA DECAPODA. 



[Oraees 37-42, 49. 51. 53. 55. 64-69]. 



The Decapod Crustaceans include the two great groups 

 of the Lobsters and Crabs, along with a third intermediate 

 group typified by the Hermit-crabs. 



All three groups are essentially alike in structure, and 

 the chief distinction between them is to be found in 

 the relative size and functional importance of the abdomen. 

 In the Lobsters the abdomen is as well developed as any 

 other region of the body, and forms a .powerful symmet- 



