A REVIEW OF THE MYSIDACEA 121 



a bathypelagic species, widely distributed in the tropical regions of 

 the Atlantic. The occurrence of young specimens in surface nets is 

 interesting, but such occurrence is probably connected with special 

 conditions existing near the Bermudas, where there is an upwelling 

 of water from the depths, which would have the result of bringing up 

 with it its contained organisms. 



Remarks. — The specimens caught in the surface nets comprise all 

 immature specimens, 12 young females and 8 young males, 6 to 9 mm. 

 The specimens from the deep water net include 2 adult females, 13 

 mm., and 2 immature males, 10 mm. The specimens agree with Zim- 

 mer's account very closely except that the rostral plate is not bluntly 

 pointed. The rostral plate has straight sides set at an angle of about 

 120° with the apex bluntly rounded. This difference at first led me 

 to think that these specimens represented a new species, but further 

 examination suggests that the difference in the rostral plate may be 

 a sexual one, since Zimmer's specimen was an adult male. There 

 are no adult males in the above specimens, but all the females and 

 young males have the rostral plate as I have described it above. The 

 difference, if sexual, does not become apparent until just before sexual 

 maturity is reached. 



One or two additional points seem worthy of note. All the speci- 

 mens of both sexes have a tuft of long setae at the base of the outer 

 and stouter flagellum of the antennule. In addition the male has the 

 usual setose lobe on the antennule. The eye papilla is much more 

 developed in the adult than in the young stage and appears to become 

 longer with age. In the adult specimens, as Zimmer shows, it is a 

 long slender fingerlike process, but in the young stages it is much 

 shorter and therefore much blunter. 



The third to the eighth thoracic limbs have a very long and slender 

 endopod, and in this respect they agree closely with those figured by 

 Hansen (1908a, pi. 5, figs, la-lo), in L. fuscus. The telson (fig. 

 40, b) agrees closely with that described by Zimmer. In all the speci- 

 mens there are four short spinules at the apex but curiously enough 

 in none of them are the spines symmetrically arranged. There are 

 no other spines or armature on the telson. 



L. capensis may be distinguished from the other two described 

 species of the genus, L. fuscus and L. si?nilervthrops, by the shape 

 and armature of the telson and the shape of the antennal scale (fig. 

 40, a). All the specimens in this collection are strikingly black in 

 color, but whether this is due to some special method of preservation 

 or whether it is the natural color I am unable to say. I mention the 

 fact, however, because L. fuscus is suffused with a dark grayish-brown 

 pigment, in life, and it is quite likely that L. capensis is also suffused 

 with a similar but darker color. 



