282 BULLETIN OF THE 
A further study of these specimens, together with those of the Jeffreys col- 
lection, has confirmed me in the opinion I expressed in my preliminary report 
as to the remarkable variability of this species, the modifications being so grad- 
ual that I am in doubt as to whether more than one species exists in our seas, 
unless the P. sublevis Verrill be different, as from the figure would seem likely, 
if it be normal. P. neeroides has a surface similar to that of P. sublevis, but 
is at the opposite extreme of form. P. rotundata has a sparse or close granu- 
lation indifferently, if one may judge by the few specimens I have seen. I 
find among the specimens collected some small, inflated, and triangular, com- 
pared with the average of the others, in which the granulation is composed of 
beautiful minute spheres, perfectly transparent and closely set in quincuncial 
arrangement with the greatest regularity. They agree in most details with 
the description given by Smith of his australis, The granulation is coarser 
than in the average granulata, and the effect of the light upon the transparent 
spherules, under a glass, gives them the appearance of little cups or tubes. I 
cannot feel positive that they are the same as the form described by Mr. Smith 
without a comparison of specimens; but they agree too closely to warrant 
giving any other name to them until a comparison can be made. I have seen 
one alcoholic specimen of P. granulata in which the soft parts showed no essen- 
tial differences from Cetoconcha, The lower palpi were present and the siphons 
not very long. 
Poromya (Cetoconcha) albida, n. s. 
Shell not pearly externally, white, thin, punctate and polished toward the 
beaks, toward the margin with rather sparse granules covered with a thickish, 
wrinkled, straw-colored epidermis ; beaks slightly nearer the anterior end, not 
contiguous, rather high, small, inflated, but less so than in C. tornata; both 
ends rounded, the posterior a little less inflated and more produced; base 
evenly rounded; interior strongly radiately striate ; muscular impressions 
high, narrow, impressed; right valve with the hinge-line obtusely arched, the 
centre under the beaks with a solid triangular thickening ; the anterior end 
of this supports a stout, short, round-topped cardinal tooth, behind which the 
callus supports on its dorsal surface a stout triangular cartilage, the anterior 
end of which probably appears between the anterior bifurcation of the external 
ligament, but the posterior apex of which is internal and covered by the liga- 
ment ; the ligament, as in all this group, turns away from the hinge-line and is 
lost under the beaks; above its course is an elevated narrow ridge which ex- 
tends posteriorly to the end of and very close to the hinge-line. Lon. 21.5 ; 
alt. 19.5 ; diameter of the valve 8.5, and of the whole shell probably 17.0 mm. 
A single right valve was obtained by the Fish Commission at Station 2159, 
in 98 fms., near Havana, Cuba. The shell resembles Poromya sublevis Verrill, 
but has twice or three times the size; otherwise, until the hinge is critically 
examined it would pass for that species. It is, however, larger than any known 
Poromya. 
