84 
Memoirs of the Indian Museum. 
[VOL. II, 
There can be little doubt that the degeneracy of these rami brings the subgenus 
into close relationship with the Alepadinæ, and it is noteworthy that the mandibles of 
the species of both subgenera show a certain approximation in form to those of the 
species of that degenerate subfamily. Degeneracy in the mandibles consists, however, 
ver}^ largely in a reduction in the number of their teeth, and it must be noted that a 
reduction of the kind takes place occasionally, as an individual peculiarity, in widely 
separated families. For instance, in some examples of Pœcilasma minutum two 
of the central teeth fuse together, as a rule onl}^ on one mandible ; while in the speci- 
men of Scalpellum sociabile which was first dissected the large outer tooth of both 
mandibles had completely disappeared, although in other specimens from the same 
locality since examined it has been found to be well developed.^ However this may 
be, it seems clear that the genus Heteralepas {sensu lato) affords a link between the 
subfamilies Fepadinæ and Alepadinæ. It may be necessary later, however, as Pilsbry 
points out, to separate Paralepas from Heteralepas as a distinct genus. 
Only two species of Heteralepas have been as yet recorded from Indian seas, one 
representing each subgenus. They are — 
Heteralepas {Paralepas) xenophoræ , mihi, 
and 
Heteralepas {Heteralepas) nicobarica, sp. nov. 
Subgenus Paralepas, Pilsbry. 
Heteralepas {Paralepas) xenophoræ (Annandale). 
Alepas xenophoræ, Annandale , Ann. Mag. Nat. Hist. (7), vol. xvii, p. 399 (1906); 
Illustr. Zool. “ Investigator Crust. Ent., pi. ii, figs. 5, 5a, 5b ; Hoek, Siboga- 
Exped., Mon. xxxi^?, Cirr. Ped., p. 39. 
Capitulum subtriangular, pointed at the apex, slightly inflated below the aper- 
ture (at the base of which there is a distinct constriction), marked with transverse 
striæ. Aperture slit-shaped, with barely protuberant lips, rather less than a third as 
long as the vertical length of the capitulum. No scuta. 
Peduncle stout, irregularly but fineh^ annulated, longer than the capitulum. 
Cirri, etc. — Cirri short and feebly curved, with the pedicel long as compared 
with the rami. First cirrus widely separated from the .second, each of its rami with 
five distinct joints, of which the proximal joint equals the sum of the others in 
length; the anterior ramus with a soft, easily broken cylindrical process at its tip; 
this ramus distinctly broader than the other and longer by one complete joint ; the 
basal joint of each ramus broadly convex outwards on the posterior margin, the other 
joints having this margin nearly straight and the anterior margin more or less convex ; 
each joint of both rami bearing a circle of stout feathered bristles round its distal ex- 
tremity and each basal joint with a dense fringe of similar bristles running down both 
' I have satisfied myself that this is so by re-examining my preparations of the type specimen, and 
by dissecting several others [see Mem. Asiat. Soc. Bengal, vol. i, p. 78, fig. 2 (1906)]. 
