KEMP—PELAGIC CRUSTACEA DECAPODA 61 
Oct. 16, 1905. 4 miles N.W. of Desroches Atoll. Il. 750 to 0 fms.; one male. 
The two male specimens agree closely with the description of the type published 
in 1909. The mid-dorsal carina of the carapace is, however, continued as far as the 
posterior margin, and the distance between the gastro-hepatic and cervical grooves”, 
though somewhat variable, seems always to be less than one-quarter the distance from 
the latter groove to the posterior edge. The description of the type specimen, which was 
badly damaged, is probably unreliable in these respects. 
Considerable variation exists in the form of the mandibular palp, and this is note- 
worthy owing to the importance which Bouvier has assigned it as a specific determinant. 
In the type the ultimate segment is longer than the greatest width of the basal segment ; 
but in the two males in the present collection the proportions are different. In one the 
last segment is in length about equal to the width of the basal segment, while in the 
other it is even shorter. 
The third segment of the endopod of the first maxillipedes is, in these specimens, 
only one and a half times the length of the second. In the first pair of pareeopods, which 
was missing in the type, the carpus is a little more than two-thirds the length of the 
merus, and is about as long as the chela. 
The petasmata of the two specimens are as nearly as possible in exact agreement 
with that of the “Challenger” example (Joc. cit., pl. lxxv, fig. 1). The distal lobes are, as 
usual, bent inwards and outwards in a very curious manner and, when seen from below, 
present the appearance shown in fig. 6. 
Six females, four of which were taken in the same net as one of the males 
already mentioned, are also referred to this species, the female of which was previously 
unknown. The evidence for this determination is, as I have outlined above, somewhat 
meonclusive. 
The form of the thelycum is illustrated in fig. 7. It bears a very close resemblance 
to that of G. tunayrez, Bouvier, a species which in this respect exhibits a rather unusual 
amount of variation and has hitherto been found only in the Atlantic. In the present 
examples, however, the design is very constant and differs from that of G. tenayres 
in the presence of an additional pair of tubercles between the legs of the third and 
fourth pairs. 
7. Gennadas scutatus, Bouvier. 
Gennadas scutatus, Bouvier, Rés. Camp. Sci. Monaco, xxxiii. 1908, p. 42, pl. 8. 
Oct. 16, 1905. Near Desroches Atoll. mm. 400 to 0 fms.; one male, one female. 
The specimens differ from Bouvier’s description in a few unimportant details. The 
endopod of the second maxilla bears from two to four curved spines on its dorsal aspect 
near the apex. The third segment of the endopod of the first maxillipede is broadly oval 
in the male specimen, while in the female it is narrow, as shown in Bouvier’s figure. The 
widest part of the merus of the second maxillipede is, in one specimen, situated much 
closer to the distal end of the segment than is indicated by Bouvier. The apex of the 
* In previous papers I have called these grooves the cervical and post-cervical respectively; the terminology 
here employed seems preferable. 
