62 PERCY SLADEN TRUST EXPEDITION 
telson, which is only extant in the male example, is slightly convex and is furnished with 
four pairs of plumose setze. 
The petasma is quite typical and resembles that of the Atlantic specimen figured 
by Bouvier* rather more closely than that of the “Challenger” specimen} from the 
N. Pacific, and is noticeably different from that of the individuals recorded from the 
Indian Ocean, 8S. of Cape Comorm. Several additional examples bearing the closest 
resemblance to those from Cape Comorin have recently been obtained by the “ Investi- 
gator.” The differences which are noted in Rec. Ind. Mus., 1910, p. 178, pl. xin, fig. 10, 
are in my opinion sufficiently constant and well marked to entitle the form to subspecific 
rank. It may be known as G. scutatus, subsp. indicus. 
The thelycum of the female specimen collected by Mr Gardiner has the curious form 
figured by Bouvier and, except that there is a small median notch in the distal or anterior 
margin of the long plate lying between the last three pairs of legs, agrees exactly with 
his account. The triangular biperforate plate between the legs of the third pair is 
clearly seen. 
The examples are unfortunately in very bad condition, and in both the third maxilli- 
pedes and all five perzeopods are wanting. When complete neither specimen appears to 
have exceeded 20 mm. in length. 
8. Gennadas alcocki, Kemp (Plate 7, fig. 8). 
Gennadas aléocki, Kemp, Rec. Ind. Mus., 1910, v. p. 174, pl. 13, figs. 5—8. 
Sept. 27, 1905. S. by HE. of Farquhar; 10° 27’S., 51°17’ KE. p. 800 to 0 fms. ; 
one female, 24 mm. 
Oct. 16, 1905. 4 miles N.W. of Desroches Atoll. 1], 750 to 0 fms.; one female, 
26 mm. 
The basal segment of the endopod of the first maxillipede is, in one specimen, 
provided with only two spines on the inner margin, whereas in the type five are found 
in this situation. Bouvier, in his exhaustive memoir on the Atlantic species of this 
genus, defines the proportions and spinulation of the oral appendages at considerable 
length ; but my own experience leads me to believe that these details are very variable 
and of little taxonomic value. 
In the two examples of G’. alcock: contained in the present collection the thelycum 
is closely similar in pattern to that of the type, but in both specimens the plate lying 
between the legs of the third pair is shaped even more clearly in the form of a W than 
in the original example (see fig. 8). 
9. Gennadas sp.? (Plate 7, fig. 9). 
Oct. 16, 1905. 4 miles N.W. of Desroches Atoll. Il, 750 to 0 fms.; one female, 
ca. 24 mm. 
The rostral crest is of the usual form, and is continued backwards as a carina which 
extends to the posterior margin of the carapace. Both antennary and infra-antennary 
* Bouvier, Bull. Mus. Océanog. Monaco, 1906, No. 80, text-fig. 13, p. 11. 
+ Kemp, Proc. Zool. Soc. 1909, Pl. 75, fig. 2. 
