176 Records of the Indian Musettni. [Vol. V, 



Gennadas praecox, sp. nov. 



(Plate xiii, figs, i — 4.) 



St. 320. — Off C. Comorin, 7° 23' N., 75° 44' E., 1,053 fathoms. 

 One male, ^2^ mm. 



The rostral crest is much the same as m the two preceding 

 species, but the dorsal spine is more slender. The antennary and 

 infra-antennary angles are acute, but rather bluntly rounded at the 

 apex ; the branchiostegal spine is minute. The cervical and post- 

 cervical grooves of the carapace are deeply cut; they approach one 

 another very closely in the mid-dorsal line, where the distance 

 between them is scarcely one-sixth the distance from the post- 

 cervical groove to the hinder margin. The mid-dorsal carina runs 

 the whole length of the carapace, but is inconspicuous posteriorly. 

 The second joint of the antennular peduncle, measured dor- 

 sally, is about two-thirds the length of the ultimate segment. The 

 antennal scale (fig. i) is three and a quarter times as long as 

 broad; it is widest basall}- and its outer edge, which is nearh^ 

 straight^ terminates in a small spine which falls far short of the 

 narrow apex of the lamellar portion. 



The ultimate joint of the mandibular palp is about as long as 

 the greatest width of the penultimate joint. In the second max- 

 illa (fig. 4) the anterior lobe of the internal lacinia is strongly con- 

 stricted behind the apex and is a trifle narrower than the adjacent 

 and similarl^'-constricted lobe of the external lacinia. In the latter 

 lacinia the anterior lobe is full}^ one and a half times the width of 

 the posterior. The third joint of the endopod of the first max- 

 illipede is fully twice the length of the second ; the fourth is ex- 

 tremely minute. Two stift" curved spines are situated on the inner 

 distal margin of the joint. 



The carpus of the first pair of peraeopods is about the same 

 length as the chela and is two-thirds as long as the merus. In the 

 second pair the chela is three-quarters the length of the carpus and 

 the dactylus is shorter than the palm. The carpus of the third 

 pair is about equal in length to the merus; the chela is onh' a 

 little more than half the length of the carpus and the dactylus is 

 fully as long as the palm. 



The median spines on the abdominal sterna are blunt and in- 

 conspicuous; the sixth somite alone is dorsally carinate. The 

 telson is squarely truncate at the apex and is furnished with spines 

 and setae as in G. alcocki. 



The petasma (figs. 2, 3) is most peculiar and utterly unlike 

 that of any species hitherto described. In what appears to be its 

 natural position each of the two halves is roughly triangular in 

 shape and is provided with two long and narrow processes, one on 

 its distal and inferior aspect and one, curved and directed inwards, 

 which arises close to the superior inner margin. In place of the 

 numerous small pleats, which are usually found near the line of 

 connection of the right and left halves, there is, in this instance, a 



