No. 26.] ARTHROSTRACA OF CONNECTICUT. 161 



First gnathopods with carpus produced downward at 

 postero-distal angle into a small lobe; propodus oblong, narrower 

 than carpus but about as long, palm oblique and spinose. Second 

 gnathopods in male with carpus having front margin convex 

 and furnished at its postero-distal angle with a large, acute 

 tooth, above which is a rounded sinus separating the latter from a 

 small rounded tooth ; propodus oblong, slightly curved, nearly 

 as long as carpus, hind margin irregular; dactyl large and stout. 



Second gnathopods in female similar to first pair. Third 

 pereiopods very small ; merus with a long spatulate lobe on poste- 

 rior margin; carpus articulated to posterior margin of merus 

 above distal end of latter, and produced greatly beyond articu- 

 lation of oblong propodus ; dactyl short and broad with an 

 abruptly recurved hook-like tip. Fourth pereiopods with basal 

 joint as long as merus, longer than broad ; fifth pair more slender. 



First uropods with outer ramus much larger than inner ; 

 second pair about one-half as long as first, with a single ramus 

 which is very short and furnished with a terminal hook ; last pair 

 much like preceding but stouter. Telson with two dorsal rows 

 of sharp, upturned spinules, about twice as broad as long and 

 distally emarginate. 



Length 4.5 mm. 



Distribution: Great Egg Harbor, New Jersey; Vineyard 

 Sound, Massachusetts, in masses of the compound ascidian 

 (Amonroucium pellucidum) ; Noank iHarbor, Connecticut; 

 (Smith), Long Island Sound. 



The species occurs also in eel-grass to depths of 10 fathoms. 

 Considerable numbers were taken at the surface in the evening 

 at Noank Harbor, July 21, 1874. 



These animals construct thin cylindrical tubes which they 

 carry about with them, thus differing from the great majority of 

 tube-dwelling Amphipoda which inhabit a fixed tube. Professor 

 Smith (Trans. Conn. Acad., vol. 4, pp. 269-277) has given a full 

 description of the species with observations on its habits. 



Ericthonius Milne-Edwards. 



Body somewhat depressed, with very small coxal plates ; 

 abdomen narrow and elongated. 



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