629 



bilobed at the tip; posterior lip witli the inner lobes well defined. Oral parts 

 otherwise normal. Gnathopoda more or less unequal, the posterior ones in male, 

 as a rule, mncli larger than in female. The 3 posterior pairs of pereiopoda 

 generally very much elongated, with the basal joint narrow, and the dactylus 

 very strong. Pleopoda with the basal part not expanded inside. Last pair 

 of nropoda, and sometimes also the penultimate pair, wanting, or only pre- 

 sent as slight rudiments. Telson entire, squamiform. 



BemarJis. — The present family comprises a number of Amphipoda 

 of rather different appearance, but agreeing in the more or less imperfect 

 development of the urosome and its appendages. In all forms the last pair 

 are entirely wanting, or onlj' present as very slight rudiments, and in some 

 forms even the penultimate pair are quite rudimentary. One of the genera, 

 DiiJichia, was placed by Sp. Bate together with the Caprenidtv in his division 

 '(Aberrantiav, whereas the genus Lcrtntalopliilus was referred to the CoropldidiE. 

 Besides these 2 genera, Boeck has added 2 other northern genera, viz, 

 Xenodice and Faradtdkhia. The genus Plafophium of Dana ought also to be 

 comprised within this familj^ though it has the last segment of the urosome 

 well defined. 



Gen. 1. Lsetmatophilus, Bruzel. 



Syn.: Cyrtophium Sp. Bate (part). 



Bod}' robust, subdepressed, with a very movable articulation between 

 the first two segments of mesosome. Metasome and urosome comparatively 

 small. Cephalon with the frontal part rather produced and narrowly trun- 

 cated at the tip, lateral lobes very slight, with a dentiform projection be- 

 hind. First pair of coxal plates small, quadrangular, the 3 succeeding pairs 

 broader than they are deep. Eyes distinct and somewhat protuberant. An- 

 tennae very strong, subpediform, and densely setiferous, the superior ones 

 without any accessory appendage, flagellum in both pair.s rather short and 

 only composed of a restricted number of articulations. Mandibular palps 

 large, with the terminal joint lamellarly expanded and densely setiferous. 

 First pair of maxillae with the basal lobe rudimentary. Maxillipeds well 

 developed, with the masticatory lobes mucli larger than the basal ones. 

 Gnathopoda very unequal, the anterior ones rather feeble, the posterior ones 

 powerfully developed, and differently shaped in the two sexes. Ail pereio- 

 poda alike both in size and structure, being rather elongated, and terminating 

 in a very strong claw like dactylus. Branchial lamellae very small; incu- 



83 — Crustacea. 



