398 PROCEEDINGS OF THE ACADEMY OF [1897. 



pallida, is slightly concave. The slightly arcuate outline of the 

 thorax running into the straight outline of the abdomen differenti- 

 ates this from all other species of the genus. Other differences are, 

 the larger eyes situated nearer the margin of the head, the very 

 hairy edges of the valve, and the sparsely granulated abdomen. The 

 length of the adults from which the foregoing description is made 

 ranges from 21 to 22 mm. 



A female, about 14 mm. in length, has arcuate lateral margins, 

 and all of the tubercles of the large male are exaggerated in size ; 

 the tubercles between the eyes and the front and the pair separated 

 by the median line form a row of four large tubercles on the front. 



The young males have almost parallel sides ; the median tuber- 

 cles of the front are swollen and much eroded, as are all of the 

 prominences of the head. On each of the first four segments of the 

 thorax is a median tubercle on the transverse ridge and also a 

 smaller one in front of it ; there is another row of tubercles on the 

 sides. The sides of the abdomen are rough and warty. 



Synidotea nodulosa (Kr/yer). 



The limits of this species are hard to define. All of the species 

 with pointed abdomens are very similar, yet constitute, I believe, 

 good species. Abundant material will not unlikely show that addi- 

 tional species must be recognized. Kr^yer described nodulosa from 

 South Greenland ; Harger had several specimens from the Eastern 

 Fishing Banks and also records them from off Queen Charlotte 

 Island. 



I have not found nodulosa in the west coast collections. A dry spe- 

 cimen from Jugor Schar presented by the Royal Zoological Museum 

 of Copenhagen has the cross areolation between the eyes armed 

 with four tubercles, the two on the transverse line are slightly com- 

 pressed, those on the median line are united at the base, the poste- 

 rior one is much the larger ; the areolations between the post- 

 cephalic lobe and the cross are well elevated, coarsely punctate, 

 and divided on the median line ; the tubercles between the margin 

 and the eyes are well elevated and free from the margin. On each 

 segment of the thorax a short ridge crosses the median line, form- 

 ing a slightly elevated angular tubercle on the line. The abdo- 

 men measures at the base about four-fifths of its length, or 4.2 mm. 

 broad to 5.3 long. 



A specimen from the fishing banks of the northeast coast is prob- 

 ably nearer Kr^fyer's type than any other in the collection ; in this 

 the cross is armed with four tubercles that are much less conspicu- 



