No. 26.] ARTHROSTRACA OF CONNECTICUT. ^'] 



Ampelisca agassizi (Judd). 



189G. Byblis agassizi, Judd, Proc. U. S. Nat. Mus., vol. 18, 

 p. 599, figs. 9-1 1. 



This species is somewhat intermediate between Ampelisca and 

 Byblis, but agrees with the former genus in that the telson is 

 much longer than broad and cleft nearly to the base, in the 

 form of the last pereiopods, and in the fact that the last pair 

 of uropods project much beyond the other ones and have no 

 serrations on the opposing margins of the rami. 



It is distinguished from other species of Ampelisca found on 

 the New England coast by the fact that the body is not unusually 

 compressed, the postero-Iateral angle of the third abdominal 

 segment is not produced, the telson is broad and cleft nearly to 

 the base, and the merus of the last pair of pereiopods is pro- 

 duced distally nearly to the middle of the carpus behind. 



The species was obtained by Mr. Judd by skimming the sur- 

 face of Narragansett Bay at Newport, Rhode Island, in the 

 summer of 1893. 



Byblis Boeck. 



Corneal lens, when present, two pairs. 



Antennae slender. Mandibles rather strong; second joint of 

 palp not expanded, third joint short. Maxillae as in Ampelisca. 

 Maxillipeds with inner plate narrow and truncated at tip. 



Gnathopods very slender, especially the posterior ones. 



Last pair of pereiopods with basal joint produced posteriorly 

 to a very large lobe fringed on anterior and ventral margins with 

 short ciliated setae; propodus not at all expanded, sublinear; 

 dactyl extremely narrow and tipped by two unequal bristles. 



Last pair of uropods scarcely reaching beyond the preceding 

 pairs, rami narrowly lanceolate, not setose in female, their 

 opposite edges being more or less distinctly serrated. 



Telson short and broad and only slightly incised posteriorly. 



Byblis serrata Smith. 



1874. Byblis serrata. Smith, Rep. Com. Fish, for 1871-2, p. 

 561. 



Eyes two pairs, simple, situated very far forward on the 

 truncated head. 



