96 
Memoirs of the Indian Museum. 
[Voi.. II, 
There is unfortunately some confusion as to the species of Megalasma which 
occur in Indian seas. In 1894 Weltner described a form to which he gave the 
name Megalasma carino-dentatum. In preparing his diagnosis he had before him a 
single specimen from the ‘ ' Investigator ” collections. The specimen was returned 
to the Indian Museum but was apparently overlooked when the collection of which 
it formed a part was unpacked. I have been unable to trace it and have little doubt 
that it has perished. Pilsbry has recently (1907) suggested that this specimen, which 
it is impossible any longer to re-examine, was an abnormal one. 
A second form was described by myself in 1906 as Megalasma striatum subsp. 
minus and b>^ Hoek in 1907 as Megalasma lineatum. Hoek, after seeing the figure 
of my subspecies in the “Investigator” Illustrations, acknowledged that M. lineatum 
was a synonym, and Pilsbry has recently redescribed the form, showing that it should 
rank as a distinct species. M. minus may therefore be considered a well established 
species, if it is distinct from M . carino-dentatum. The distinctive characters of the 
latter were its reduced terga and toothed carina. I have examined over sixty 
specimens of M. minus and have found none with a toothed carina; but the relative 
size of the tergum varies considerably in this series and a tooth occurs on the carina 
on a small proportion of individuals of some species of Pœcilasma {e.g., P. minutum, 
see fig. 5, pi. vii). 
For these reasons, in the absence of a specimen of M. carino-dentatum , I think it 
will be best to regard the species as a doubtful one. 
Megalasma carino-dentatum , Weltner {species dubia). 
M. carino-dentatum, Weltner ^ Sitz. Ber. Ges. Naturf. Freunde, 1894, p. 84. 
Exhibiting the characters of the genus; the carina with a distinct tooth near 
its upper extremity; terga reduced. 
Attached to the filamentous spicules of the Hexactinellid sponge Hyalonema 
masoni, Bay of Bengal at a great depth. 
Megalasma minus, Annandale. 
M. striatum subsp. minus, Annandale, Ann. Mag. Nat. Hist. (7), vol. xvii, p. 399 
(1906); Illustr. Zool. ‘‘Investigator," Crust. Ent., pi. i, fig. 8 (1907); M. 
minus, Pilsbry, Proc. A. Nat. Sei. Philadelphia, lix, p. 409, figs, i, 3, 4, 6 
(1907). 
M. lineatum, Hoek, Siboga-Exped. , Mon. xxxia, Cirr. Ped., p. 31, pi. iv, figs. 
1—8(1907). 
Capitulum. — Carina reaching posterior angle of the tergum above, where it 
is distinctly pointed, with a regular series of f\- shaped ridges on the dorsal surface ; 
the lateral surfaces strongly ridged vertically, the lateral basal margin frequently 
irregular. Tergum subtriangular, the posterior angle narrowly truncate or irregularly 
sinuous ; the occludent margin barely ^ as long as scutal margin ; scutal and superior 
margins equal; a distinct internal tooth near the scutal margin a short distance 
