no. 1591. SCHIZOPODS FROM ALASKA— ORTMAXX. 9 



wide in N. vulgaris). Propodites of legs with 9 to 12 joints, i. e., 

 the third cormopod (first true leg) has 9 joints, the fourth and fifth 

 have 11 joints, the sixth, seventh, and eighth have 12 joints; for the 

 rest, the true legs resemble those of N. vulgaris. Telson elongate- 

 triangular, about three times as long as broad at the base, margins 

 with 20 to 23 spines, occupying a little more than the distal two- 

 thirds of the margin, the proximal part being unarmed. These 

 spines are rather uniform in size, increasing slightly and uniformly 

 toward the tip, being very crowded near the tip, while near the prox- 

 imal part of the margin they are slightly more distant from each 

 other. Spines at the corners of the narrowly truncated apex resem- 

 bling the adjacent marginal spines; between them are two small 

 spines. Uropods as in N. vulgaris. Pleopods of male resembling 

 closely those of N. vulgaris, but the distal joint of outer branch of 

 the fourth is about half as long as the proximal, and a little longer 

 than the terminal filaments. 



Type.— C^t. No. 31493, U.S.N.M. 



This species is closely allied to Neomysis vulgaris (Thompson) 

 of North Europe, but differs in the more slender antennal scale, 

 the number of joints of the propodites of the true legs, the relative 

 length of the two joints of the outer branch of the fourth pleopods 

 of the male, and in the shape and armature of the telson. N. 

 vulgaris attains a length of 17 mm. 



Neomysis americana (Smith) from the northeastern coast of 

 North America, 6 is distinguished by the evenly rounded rostrum 

 the antennal scale, which resembles that of N. vulgaris, the fourth 

 pair of pleopods of the male, in which the first joint of the outer 

 ramus is 4 to 5 times as long as the second, while the latter is little 

 more than half as long as the terminal filaments, and by the telson, 

 which resembles in shape that of N. vulgaris, and has unequal mar- 

 ginal spines, with several smaller ones in the intervals of the larger. 

 Size, 14 mm. 



Another species belonging to this genus is Neomysis rayi (Mur- 

 doch), from Point Barrow, Alaska, but this species is much larger 

 (up to 65 mm.), the rostral projection is quadrangular with rounded 

 corners, the propodites of the true legs have 8 to 9 joints. The telson 

 resembles that of N. vulgaris, but the account of it given by Murdoch 

 is not full enough to make an exact comparison. 



a Sars. Monogr. Mysid., Ill, 1879, p. 80, pi. xxxiv ; Norman, Ann. Nat. Hist. 

 (6), X, 1892, p. 261. 



6 Rep. U. S. Fish Comm., I, 1873, p. 552, and Trans. Conn. Acad., V, 1879, p. 

 106. 



c Proc. U. S. Nat. Mns., VII, 1884, p. 519, and Rep. Pol. Exp. Point Barrow, 

 1885, p. 141 pi. i, fig. 3. 



