GENNADAS. 207 



bat is distinguished at a glance by the long spine on the tergiim of the fifth 

 abdoininal 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 joint in the endopod of the third maxilliped {v. 

 Ann. Kep. 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 i?. iiiclesccns Bate. 



The number and arrangement of the branchioa of this species are shown 

 in the following table : — 



24 +(7) 



The posterior of the two arthrobranchite of the eighth somite is perhaps 

 homologous with the pleurobranchiae 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 Bate. 

 Anil. Mag. Nat. Hist., 5th Ser., VIII. 191, 1S81 ; Rep. Challenger Macrura, p. 339, 1888. 



Gennadas sp 



Hydr. 2638. 500-570 fathoms. Sub-marine tow-net. 



Station 3399. 1740 " 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. intcrmedws 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 



