No. 26.] -ARTHROSTRACA OF CONNECTICUT. 221 



than either of the preceding ones; scarcely exceeding in length 

 the first three joints of the second pair. Second antennae with 

 first three joints rather short and subequal in length; fourth 

 joint longer than third, and fifth still longer, being twice as long 

 as the third ; flagellum of about a dozen segments of which the 

 first is by far the longest and a little longer than the peduncle. 



Thoracic segments about equal in length. Coxal plates dis- 

 tinct from their segments and forming a nearly even curved out- 

 line, the segments being marked by incisions instead of serrations 

 as in the other species. 



Legs more or less alike in structure and increasing in length 

 posteriorly ; the first pair much stouter than the succeeding ones. 



Abdomen of two short segments followed by a long one which 

 shows indications of coalescence of a third short segment, lateral 

 angles of first two abdominal segments acute. Telson with lateral 

 margins slightly convex and with apical margin produced in 

 middle to an acute point which extends some distance beyond the 

 lateral angles. Operculum with peduncle three times as long as 

 the terminal ramus which is broadly truncate at the apex. 



Color varying greatly ; frequently nearly uniform light or dark 

 green, or brownish with blackish punctations. Females usually 

 darker than the males which often have a median dorsal stripe. 



Length of males 30 to 38 mm. ; of females 20 mm. 



Distribution: Java; Red Sea; New Zealand; Scandinavian 

 coast; Baltic Sea; west coast of Europe to Great Britain; Medi- 

 terranean ; Caspian, and Black Seas ; Bermuda ; Barbadoes ; Rio 

 Janeiro; North Carolina north to Nova Scotia and the Gulf of 

 St. Lawrence. Within Connecticut the species has been collected 

 at New Haven, Stony Creek, Lyme, Noank, and off Stonington. 

 From Cape Cod southward the species is abundant, but towards 

 the north it is replaced by /. phosphorea. 



The species occurs on the surface, on floating seaweeds, some- 

 times far from land. More commonly it is found among sea- 

 weeds along the rocky shores of bays or sounds, and among the 

 rocks at low water. In the Woods Hole Survey it was occasion- 

 ally brought up in the dredge while operating at depths as great 

 as 1^/2 fathoms; but the specimens may have been taken in these 

 cases near the surface. 



