872 PROCEEDINGS OF THE NATIONAL MUSEVM. vol.xxi. 



seta'. Mandibles large and powerful, bearing on the inner surface a 

 broad, ridged molar tubercle; on the anterior surface, one or two deli- 

 cate, branched sensory styles. The cutting portion of the mandibles 

 is different; that on the left, consists of two portions, an outer with 

 four heavy teeth and an inner with three much smaller teeth; the 

 other mandible has but one row of three or four large teeth which, when 

 closed, fit in the space between the two rows of teeth of the mandible 

 first described. The first maxilla has both branches erect, the outer 

 bearing five or six acute curved teeth, the inner three delicate plumose 

 flagelliform processes. The second maxilla consists of two strap-shaped 

 lamella} closely applied to one another and bearing seta3 at their ends. 

 The maxilliped is a broad, flattened plate, with straight inner and 

 rounded outer margins, and bearing at the tip two obscurely segmented, 

 setose processes. The per?eopods are similar in general to one another, 

 differing only in the arrangement and strength of the spines. 



The first and second pairs of pleopods are two-segmented, slender, 

 and styliform. The second pair appear to be the sexual organs, while 

 the first are to some degree rudimentary. 



The third pleopod is flattened and somewhat operculiform. 



The fourth and fifth pleopods are broad, flat, thin, and lie flat upon 

 one another and the last segment of the pleon. They and the preced iug 

 are the branchial appendages of the animal. 



The uropods have been already described. 



Color, white; eyes, black; intestine showing through the shell as a 

 grayish line. 



Female. — Similar in general characters to the male, but with the fol- 

 lowing differences: Body not more than two and one-half times as long 

 as wide. First and second pleopods absent. Per;copods with flattened 

 plates, forming a brood or egg chamber. 



Length, 3 to 4 mm, 



Type.—Eo. 22586, U.S.N.M. 



• EXPLANATION OF PLATE LXXXVl. 



Fig. 1. Dorsal view of a male specimen. 



2. Maudible of right side, seen from in front. 



3. Mandible of left side (tip only), to show double row of cutting teeth and 



ridges on molar tubercle. 



4. First maxilla. 



5. First maxilliped. 



6. Upper lip. 



7. Antenna (second antenna). 



8. Antennule (first antenna). 



9. First periL'opod. 



10. First pleoj)od. 



11. Second pleoijod. 



12. Third pleopod. 



13. Fourth pleopod. 



14. Fifth pleopod. 



15. Uropod (right side). 



