AMPHIPODA OF SOUTHERN NEW ENGLAND. 465 



podus and devoid of setae; outer ramus of uropods much shorter than inner; telson not one-fourth the 

 length of peduncle of terminal uropods. 



Length, 12-30 mm., the latter attained by Arctic specimens. 



Norway (Sara); Arctic Ocean; Greenland; Jeffries Bank, Labrador; off Marthas Vineyard, Alba- 

 tross stations 914, 2029, 2095, 2101, 2255. 



This species, like the following one, is often taken in large quantities at the surface. Frequently 

 many hundred specimens are taken without a single adult, or numerous adults may be taken without 

 finding a single immature individual. The teeth on the dorsal side of the thorax and abdomen are 

 often absent entirely in the young of both species. 



Euthemisto bispinosa (Boeck). 



Body carinated above, the carina on last two thoracic segments produced posteriorly in adults into 

 a tooth; antennae about as in comprextm; first peneopods with carpus irregularly oval, much broader 

 than in compressa, the posterior margin bulging strongly backward near the proximal end and furnished 

 with several rather weak seta-; carpus of second peneopods oval, broader than in romprrxxn, the seta> 

 on posterior margin much as in first pair; third peneopods large, much elongated; carpus markedly 

 stouter in the basal half; propodus very narrow, elongated and straight, anterior margin furnished 

 with but few sette, mainly on proximal portion and pectinate with minute spinules which increase in 

 length toward distal end, where they may equal or exceed the diameter of the joint; dactyl devoid of 

 setae and less than one-fifth the length of propodus; uropods and telson as in preceding species. 



Arctic Ocean; Finmark; Greenland; off Nova Scotia (Stebbing); Gulf of Maine; Vineyard Sound; 

 Grampus station S9; Long Island. 



Family PHRONIMID£. 



Very deep head, on the sides and top of which are located the large eyes; antennae attached to 

 anterior side of head, the flagellum of both pairs multiarticulate in the male; second antenna- rudi- 

 mentary in the female; no mandibular palp. 



Phronima sedentaria (Forskal). 



Several specimens of this species, from various points off the coast of New England, were examined. 

 They were usually found in tests of Salpa. The species is very extensively distributed over both the 

 Atlantic and the Pacific oceans. The variations due to differences of age and sex are very great and 

 have given rise to much confusion and the formation of many synonyms. " 



Tribe GAMMARIDEA. 



Head rather small, with eyes rarely of very large size; body usually compressed; maxillipeds with 

 inner plates free and furnished with a palp. 



The Gammaridea include the typical Amphipoda. Both the Hyperiidea and the Caprellidea are 

 to be regarded as aberrant groups, highly specialized in relation to their peculiar habits of life. The 

 Gammaridea comprise by far the greater number of species of amphipods. The group is one of great 

 diversity, and its proper subdivision is attended with unusual difficulties. There are extremely wide 

 differences of opinion regarding the limits of the families into which it should be divided. In the 

 elaborate monograph of the Gammaridea by Delia Valle, all the genera are grouped into ten families; 

 Sara distinguishes twenty-five families in the fauna of Norway alone, and several new families have been 

 instituted by Doctor Stebbing. At present a large number of families is proposed without being grouped 

 into anything that approaches a satisfactory system. In the present paper I have not attempted the 

 task of grouping the genera into families, as it was not really necessary for the purpose in hand, and 

 have inserted a key which enables one to pass directly to the genera. 



a I subjoin a list of species of Hyperiidea examined from regions somewhat beyond the one covered by this paper. 



Paratb&nisto <>t'li>:io (Kroyer); Albatross stations 2029 and 2101. 



Cystisoma spinosum ( Fabricius), a single specimen; Albatross station 2199. 



OxycepJuUus clausi (Bovallius); Albatross station 2095. 



Anchylomi rn BlosSi vUlii i Milne-Ed wards); Gulf stream, several specimens. 



Vilnlin matrix I Bovallius); a single specimen from off Newport. 



An undetermined species oi Thyropus is reported by Professor Smith as having been taken off Gay Head. 



