Invertebrate Gallery of the Indian Museum. 75 



transporting the sea-anemone to fresh feeding 

 grounds. This is another instance of that per- 

 manent association of two animals of different 

 species for mutual benefit which is known as 

 "commensalism." 

 Dorippe and Ethusa (Case 68) are Indian representa- 

 tives of this family, the first being a common shallow-water 

 form, the last occurring in the great depths of the ocean. 



5th Tribe, Anomola, Case 68. — The three families, Dro- 

 midsSt Homolidae and Ramntdx, of which this tribe 

 consists, were formerly placed with the Anomura. They 

 are here united with the Crabs in accordance with the 

 teaching of the late Professor Wood-Mason. 



1st Family, Dromidse — represented in the collection 

 by Dromia and Cryptodromia. These Crusta- 

 ceans commonly live commensal with Sponges, 

 the sponge forming a cap beneath which the 

 crab is completely hidden : they are common on 

 the coral reefs of the Andaman Islands. 

 2nd Family, Homolidse — represented in the collection 

 by Paromolopsis from the depths of the Anda- 

 man Sea and Hypsophrys from the depths of the 

 Laccadive Sea. In the Homolidse the orbits 

 are very incomplete, and the last pair of legs 

 are very small and are placed on the back. 

 3rd Family, Raninidee — represented by Ranina, Rani- 

 noides, Notopus, and Lyreidus, all from the 

 Indian Seas. In shape these curious Crustaceans 

 have a resemblance to a frog. The carapace is 

 . long and the last pair of thoracic legs, which 

 are very small, are carried on the back. 



y, DEOAPODA ANOMURA. 



r<2ra0£0 42 mil 49]. 

 The Anomura are in many respects intermediate 

 between the Macrura (Lobsters) and the Brachyura 

 (Crabs). 



