212 G. M. Giles — Six neiv Amjjhipods from the Bay of Bengal. [No. 2, 

 Explanation of Plate II. 



Fig. 1, 2. The external appearance, natural size, of some of the nodules. 



Fig. 3. A thin slice treated with hydrochloric acid and seen between crossed 

 Nicol's prisms j shewing the dark crosses and radiating structure of the aggregates. 



Fig. 4. A thin slice shewing some of the enclosed Foraminifera as seen by or- 

 dinary light; from a microphotograph (Smith and Beck's W obj.) taken in the Bio- 

 logical Laboratory of the Indian Museum, Calcutta. 



XV. — Natural History Notes from H. M.'s Indian Marine Survey 

 Steamer * Investigator', Commander Alfeed Carpenter, R. N., Com- 

 TYianding. No. 6. On Six new Amphipods from the Bay of Bengal. — 

 By G. M: Giles, M. B., F. R. 0. S., Surgeon-Naturalist to the 

 Marine Survey. 



[Received and Read March 2nd, 1887.]. 

 (With Plates III— VIII.) 



Contents. 



§ 1. A description of two new Species (i. Phronima hucephala and ii. Phroni- 

 mella hippocephala) of the Amphipod Family Phronimidce, with some Remarks on 

 the Genera of the Family. 



§ 2. Rhabdosoma investigatoris. 



§ 3. Amphipronoe longicornuta. 



§ 4. Lestrigonus hengalensis. 



§ 5. Eurystheus hirsutus. 



§ 1. A Description of two new Species of the Amphipod Family Phro- 

 nimidse with some Remarks on the Genera of the Family. 



The genus Phronima of the division Hyperina and family Phroni- 

 midoe is a very limited and peculiar one. The species that belong to it 

 are remarkable for their bizarre form, and for the circumstance that 

 the head is considerably prolonged downwards, like that of a quadruped, 

 in a direction at right angles to the long axis of the body. 



The number of joints in the legs appears to be less than the normal 

 seven. This is due, on the one hand, to the coxal plates being fused with 

 the pleuron of each segment, and, on the other, to the circumstance that 

 the dactylopodite is in most instances very small or reduced to a mere 

 rudiment. Spence Bate* gives as a generic character that the 6th 

 thoracic appendage (third pereiopod) has the dactylopodite fused with 

 the propodite. This is, however, I am inclined to believe, an error, 

 arising probably from the want of fresh specimens. Such also appears 



* Catalogue of Amphipodous Crustacea in the British Museum, p. 316. 



