REPORT ON THE AMPHIPODA. 723 



Remarhs. — The specific name refers to the place of capture. The numerous differ- 

 ences between this species and Acontiostoma pepinii have been already mentioned, but 

 it is rather remarkable that two species of a new genus should have been taken at the 

 same time and place, represented by specimens of the same size and resembling one 

 another in so many particulars. 



Family Valettid^, n. fam. 



Mandibles. — The cutting edge strongly dentate ; a secondary plate only on the left 

 mandible ; molar tubercle prominent; palp three-jointed ; articular condyle wanting. 



First Maxilla?. — Spines of the outer plate fewer than eleven ; the palp two-jointed. 



MaxiUipeds. — The inner plates with more than three apical spine-teeth. 



Upper Antennse. — The peduncle short and stout, the second and third joints very 

 short, the first joint of the flagellum long, carrying a large brush of cylindrical filaments ; 

 a secondary flagellum present. 



Second Gnathopods subchelate, slightly weaker than the first. 



The body and side-plates not deep. 



Perieopods of the last three pairs with the first joints not overlapping. 



Remarh. — In establishing a new family for a single genus containing a single species, 

 the choice of characters must be to a certain extent arbitrary ; in the above definition 

 it is the combination of the forms there described for the mandibles and the upper 

 antennse that may be regarded as the most essential part. 



Genus Valettia, n. gen. 



Fi7'st Maxilla with the inner plate carrying more than two plumose setae. 



Second Maxillae with the plates short, not narrow. 



MaxiUipeds w^ith the inner margin of the outer plates almost smooth, apically 

 produced ; palp four-jointed, second joint not longer than the first. 



Gnathopods of the first and second pairs similar, subchelate, both with strong oblong 

 hands and definite palms. 



Uropods biramous, successively shorter ; the upper ramus in each pair shorter than 

 the under. 



Telson short and broad, partially cleft. 



The generic name is chosen in compliment to the Baron Adolphe de la Valette, who 

 early displayed his acuteness as a naturalist in investigating Amphipoda. 



By its antenna3 and pleon this genus might belong to the Lysianassidse 

 of Boeck. The mandibles would rather place it among the Pontoporidae, but that 



