PACKAED.] PHYLLOPOD CRUSTACEA OF NORTH AMERICA. 621 



at the articulation on the outside, and a short, rounded, nearly semi- 

 circular process on the inside near the base, about its own diameter from 

 the base; second joint broad, flattened, continuous with the third joint, 

 strongly curved ; outline nearly regularly convex on the outside, until 

 near the middle it suddenly bends iuward, forming an obtuse angle, 

 beyond which the outline is concave to the last articulation, where it 

 becomes again convex, forming on the last joint a slight, rouuded angle ; 

 the inner edge is nearly straight, or but slightly concave, to the last 

 articulation, where there is a slight but distinct angle; last joint tri- 

 angular, longer than broad, tapering to the acute, slightly-excurved 

 point. Ovigerous pouch of the female, when seen from below, flask- 

 shaped. "In tubs of salt-water on railroad-bridges, New Haven, Conn., 

 and Boston." — (Verrill.) 



A. Monica^ Verrill. — "A little larger and stouter than A. gracilis. Male- 

 claspers relatively stouter ; the hook, or outer two joints, being much 

 broader, more triangular, and less elongated. Caudal appendages 

 smaller, and sides of egg pouch less angulated on the sides than in A. 

 gracilis.'''' Mono Lake, California. 



A.fertilis, Verrill. — " Larger than eitberof the others, some of the speci- 

 mens being three-quarters of an inch in length. Male-claspers stout, 

 with the second joint broader and more triangular than in either of the 

 preceding species. Great Salt Lake, Utah." — (Verrill.) 



Branchinecta. — Form rather slender, wuth the median appendages 

 longest, so as to somewhat resemble Artemia in outline, but larger. 

 Male with rather slender, rounded, two-jointed claspers. Egg-pouch 

 much elongated. 



B. arctica, Verrill. — "Male-claspers rather long and slender; basal 

 joint but little swollen, elongated, regularly curved, with a small tooth 

 or prominent angle at the articulation on the inside, and on the inner 

 side a row of numerous small, distinct, sharp teeth, extending from th% 

 articulation about half-way to the base, and arranged somewhatobliquely ; 

 second joint slender, reguhirly curved, tapering to a blunt point, the 

 inner edge minutely serrulate. Egg-pou(;h of female much elongated, 

 slender, subcylindrical." — (Verrill.) In a small pool, north shore of Ham- 

 ilton Bay, or Invuctoke Inlet, Northern Labrador (Packard.) 



B. Grcenlandica, Verrill. — "A little stouter than B. arctica; the largest 

 male 17 millimeters long. Clasi)ers similar to those of B. arctica^ but 

 more elongated ; the basal joint less curved, and the second joint longer, 

 less regularly curved, tapering more quickly at base, and, consequently 

 more attenuated beyond the middle, with more slender tips, M-hich are 

 nearly straight. The tooth on the inside of the first joint is rather more 

 proininent, but the row of teeth along the inside is similar. Caudal 

 appendages stouter, tapering more rapidly. Greenland." — (Verrill.) 



B. Color adensis. Pack. (Fig. 12, male, female, and head of female). — 

 Differs from B. Grcenlandica, its nearest ally, in the basal joint of the 

 claspers being less curved, slightly shorter, this and the second joint 

 being entirely unarmed. The second joint is sinuous, not tapering, 

 swollen, and bent in slightly at the tip when seen in outline, but seen 

 in front broad and flat, subspatulate. Caudal appendages rather stout, 

 broader at base, and not contracting as in B. Grcenlandica. Length, 

 0.57 inch. Colorado, one 9 from a " pond on a mountain near Twin 

 Lake Creek, Colorado; elevation, 12,500 feet." — (Ha.vden's Survey of 

 Colorado, 1873 ; collected by Lieut. W. L. Carpenter, LT. S. A.) About 

 a hundred males, and females, with eggs, Colorado, Dr. Viele (Mus. 

 Comp. Zool. Cambridge). No date. 



It will be interestiug to determine whether these three forms are 



