On Crustacea from Goree Island, Senegambia. 259 
(No. 32, p. 365), which, presenting a membranous form when 
stretched across the irregularities of the detritus of the sea- 
bottom in which it may be growing, can be satisfactorily 
examined with the microscope, when it is found to be com- 
posed of an extremely thin transparent layer or epidermis on 
each side, enclosing one of polygonal cells of different sizes, 
indistinctly defined, but filled with granules, and apparently 
each containing a nucleus. In this membrane may be ob- 
served minute foreign bodies, such as fragments of sponge- 
spicules &c.; but their presence is only a part of what is 
taking place generally with the detritus under the spreading 
growth and agglomerating influence of this ruby-coloured 
organism, whose ‘ granules” appear to bear the colouring- 
material. ‘This is all that I could make out of Halisarca 
rubttingens in the dry state; and therefore, like Schmidt, 
have stated that further observations in the wet state or while 
living are necessary for its elucidation. 
XXVI.—On a Collection of Crustacea made by Baron Her- 
mann-Malizam at Goree Island, Senegambia. By KDWARD 
J. Mimrs, F.L.S., F.Z.8. 
[Continued from p. 220. | 
Pilumnoplax sulcatifrons, var. atlantica, n. 
Pilumnoplax sulcatifrons, Stimpson, Proc. Ac. Nat. Sci. Phil. p. 93 
(1858). 
I thus designate, with much hesitation, a small female 
crustacean which agrees in nearly all its characters with 
specimens from the “‘ Hastern seas”’ inthe Museum collection 
that are referred to Stimpson’s species, of which, however, I 
have seen no typical specimens. ‘The Oriental examples have 
lost their ambulatory legs, but agree in the form of the cara- 
pace and the antero-lateral marginal teeth, the notched and 
sulcated frontal margin, and the structure of the antenne with 
the West-African specimen. This latter has somewhat 
slenderer chelipedes—acharacter that cannot be depended upon, 
in the absence of males from the same locality for compari- 
son. Length 33 lines (nearly 8 millim.), breadth about 
41 lines (10 millim.). 
I may add, as further points of distinction, that there are a 
few granules near the base of the second antero-lateral tooth, 
and the sulcus reaching from the fourth tooth to the cardiac 
region is obsolete in the West-African specimen. 
18* 
