BALCH: LIST OF MARINE MOLLUSCA. 
145 
Eumeta subulata Montagu. Cerithiopsis emersonii (C. 13. 
Adams). Smith and Prime (’70), p. 397. Verrill (’73), p. 648. S. 
With the preceding but uncommon. 
Cerithiidae. 
JBittium alternatum (Say). JB. nigrum (Totten). Verrill (’73), 
p.648. Cerithium sayi Menke. Smith and Prime (’70), p. 394. S. 
Abundant on the mud flats, on Ulva, etc. August 23d, young of 
2-3 mm. and about 6 whorls were extremely abundant on black 
mud and sand in a few inches of water, almost covering the surface 
for some acres. 100 were easily picked from a square foot or two. 
The young at this stage and until they have attained a length of 
some 5 or 6 mm. show characters very different from the adult in 
color (which is darker), the sculpture, and the aperture, which is 
markedly different from, — and even less typically cerithioid 
than, — that of the adult. This young stage, presumably the first 
year’s growth, is often discernible in the color and sculpture of the 
spire-whorls of the adult as Gould (’70) also has observed. A 
parallel stage in apertures appears in some West Indian species of 
Cerithium. No protoconch was observed. 
Gymnoglossa. 
Pyramidellidae. 
Turbonilla sp.? 
One specimen. Kindly identified for me by Miss Katherine J. 
Bush as species designated as f r in MS. of Bush and Verrill 
which it is to be hoped may be published soon. 
Turbonilla sp. ? 
Common. Kindly identified by Miss Bush as species G."; cf. 
supra. 
Turbonilla sp. ? 
Two specimens. Kindly identified by Miss Bush as species E ; ", 
cf. supra . 
Turbonilla sp.? 
Two specimens. Kindly identified by Miss Bush as species V; 
cf. supra. 
