350 



MEMOIRS OF THE NATIONAL ACADEMY OF SCIENCES. 



The fourth pair of pereiopods (Fig. 48) end iu short bifid dactyles, the terminal claw bearing 

 a shorter proximal oiie below. The propodus is superficially segmented into from five to seven 

 rings, which vary in size. The right propodus may have five rings, the left seven. The carpus is 

 articulated into ten to twelve segments, commonly twelve, of variable or equal size. The fifth 

 pair of pereiopods is similar to the fourth, but shorter. The propodus bears from six to seven seg- 

 ments, the carpus from eight to twelve. In the fourth and fifth thoracic legs the number of 

 rings into which the propodus aud carpus are divided differ within the above limits in different 

 individuals of either sex and on the right and left sides of the same individual. The pleopods are 

 all biramous, excepting the first pair, iu which the endopodite is suppressed as shown in Fig. 44. 

 This pair of appendages is much smaller in the male. In the female the first swimmerets are 

 nearly as long as the following pairs and are fringed with long setae. 



Measurements (in millimeters). 

 [Locality: Nassau, New Providence, Bahama Islands.] 



