34 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I28 



flagellum not quite as long as the fifth peduncular joint and composed 

 of four joints. Mandible is without palp, but it may have been lost 

 in dissecting. Maxilla i, inner plate rounding and without setae; 

 outer plate bearing 4 or 5 long spine teeth and i short one; palp 

 appears to be i -jointed, obliquely truncate, and bears 4 or 5 apical 

 teeth or spines. Maxilla 2, inner plate with 3 apical spines and i 

 slender lateral spine. 



Gnathopod i small, second joint as long as the fifth and sixth 

 combined ; fourth joint produced a little forward ; fifth joint half the 

 length of the sixth and produced below into a forward-projecting 

 lobe; sixth joint widest in the middle, palm longer than hind margin 

 of joint, very oblique, slightly concave, bearing 2 slender spines and 

 armed throughout with very fine teeth; seventh joint slightly curved, 

 as long as palm, and bearing 2 setae on inner margin. Gnathopod 2 

 slender, second joint not quite as long as the sixth; fifth joint short 

 and produced below into a narrow forward-pointing lobe; sixth joint 

 long and narrow, the sharply produced distal end being opposed by 

 the long and narrow seventh joint forming a chela. 



The first and second peraeopods linear and longer than the follow- 

 ing peraeopods ; the fourth joint very little expanded, and the seventh 

 joint slender and over half the length of the sixth. Peraeopods 3 to 5 

 slender and subequal in length; fourth joint very little expanded; and 

 the seventh joint over half the length of the sixth. Coxal plates 2 to 4 

 much deeper than their respective segments. The fourth coxal plate 

 is very large and completely covers all the peraeopods when they are 

 folded. 



The metasome segments are produced backward below but not 

 sharply. The first urosome segment is compressed dorsolaterally, 

 forming a thin keel or lamella which does not project backward over 

 the telson. The second and third urosome segments are coalesced. 

 Uropod I extends back a little beyond uropod 2, and uropod 2 beyond 

 uropod 3. Very few spinules could be observed on the uropods. The 

 telson is rather long and narrow, lies horizontally, and extends back 

 a little beyond the end of the peduncle of uropod 3. Length of the 

 female figured about 2 mm. The other specimens taken were slightly 

 smaller and were all females. 



Type. — A female, U.S.N.M. No. 93547, taken in 120 feet of water 

 off Point Barrow base, Alaska, September 15, 1948, by George E. 

 MacGinitie. 



