GENNADAS. 207 
but is distinguished at a glance by the long spine on the tergum of the fifth 
abdominal somite. B. moratus Smith, another allied species, differs in having 
a distinct hepatic spine, a much broader merus joint in the second maxilliped, 
a differently shaped distal jot in the endopod of the third maxilliped (2. 
Ann. Rep. U. S. Fish Comm. for 1882, Plate X., Fig. 5), and in the existence 
of small exopods at the bases of all the thoracic appendages. 
In one abnormal specimen (a female) from Station 3436 the anterior tooth 
of the upper margin of the rostrum is wanting. The rostrum of this speci- 
men has thus the general form of the rostrum of B. dridescens Bate. 
The number and arrangement of the branchiz of this species are shown 
in the following table : — 
Somite VII. VIII. IX. Xs Xs di, SdH0h ) Sony, 
Pleurobranchie 0 0 1 1 1 1 1 16 
Arthrobranchie 1 2 2 2 2 2 2 O=13 
Podobranchie 0 1 il 1 al 1 0 O55 
Epipods 1 i if 1 1 1 1 = (7) 
244 (7) 
The posterior of the two arthrobranchiz of the eighth somite is perhaps 
homologous with the pleurobranchiz of the following somites. It is a small 
organ, as is the pleurobranchia of the ninth somite also. The epipods 
borne by the appendages of the seventh to the tenth somites inclusive 
are vesicular. 
Color when alive, deep red, with a large patch of bright blue on the back 
of the second, third, and fourth abdominal segments ; eyes black. 
GENNADAS Bare. 
Ann. Mag. Nat. Hist., 5th Ser., VIII. 191, 1881; Rep. Challenger Macrura, p. 339, 1888. 
Gennadas sp. 
Hydr. 2638. 500-570 fathoms. Sub-marine tow-net. 
Station 3399. 1740 s 1 male. 
The specimen from Station 3399 is 60 mm. in length. It is badly muti- 
lated, wanting the third pair of maxillipeds and the last two pairs of thoracic 
appendages. The tubercle on the inner side of the eye-stalk is pointed, as in 
G. intermedius Bate, but the mandibular palpus is much longer than described 
for that species, reaching nearly to the middle of the antennal scale. 
The merus of the second maxilliped is broad and operculiform. The 
