North American Species of Diaptomus. 157 



the prehensile antenna of the male (PL XXX., Fig. 7) with a 

 slender process, long and straight, having a slight appearance 

 of an apical curve, and extending beyond the penultimate 

 article and sometimes almost reaching the end of the last 

 article. 



"Setse of swimming feet unusually long. Outer ramus of 

 the fifth pair of feet in the female (PI. XXX., Fig. 5) In- 

 articulate; unguiform process of second article slightly 

 curved and minutely ciliate without. Inner ramus small 

 and almost rudimentary, with acuminate apex. 



"Eight foot of the fifth pair of the male (PI. XXX., Fig. 6) 

 large but slender ; the second article of the outer ramus with 

 marginal spine minute and placed above the middle. Ter- 

 minal claw thick toward the base, rather short, and partly 

 minutely ciliate within. Inner ramus very small and quite 

 rudimentary. 



"The left foot of the same pair very similar to that of J>. 

 siciloides and D. signicauda; the second article of the outer 

 ramus almost elliptical, the inner margin slightly emarginate 

 and partly ciliate at the lower part ; with a large and obtuse 

 apical spine and a smaller inner spine. Inner ramus simple, 

 attenuate toward the apex, and extending about to the middle 

 of the second article of the outer ramus. 



"Length of female 1-1.1 mm ; of male hardly 1 mm. 



"Found in Greenland, 61° 30'- G9° N. Lat., by Dr. C. 

 Nystrom and N. 0. Hoist, and at St. John's, Newfoundland, 

 by the former. 



"This species is distinguished from others by its minute 

 size and by the fifth pair of feet. The female bears only two 

 eggs. D. minutus has been found in the Isle of Disko, north- 

 ern Greenland, but it seems to be more common in the 

 southern part. It is without doubt spread over the northern 

 part of North America, since it has also been found at St. 

 John's, Newfoundland."* 



"We are able to confirm in every respect the description 

 given above by Professor Lilljeborg. We have, in fact, recog- 

 nized some rare specimens of D. minutus in a collection 



*Lil]jeborg's description from deGuerne et Richard, 89b. 



