186 PROCEEDINGS OF THE ACADEMY OF 
ginals (fig. b) are but a modification of these laterals, by the 
greater development of the reflection, and shortening of the inner 
cusp. The outer marginals (fig. c) become wide, low, irregular in 
shape; the upper edge broadly reflected, the reflection reaching 
the lower edge of the base of attachment, and bearing along its 
whole length numerous (6 or 8 in some teeth) short subequal 
denticles, some bluntly rounded, others longer and sharp, giving 
a pectinate appearance. 
My study of this membrane confirms my belief of the identity 
of the species with the European form. I have carefully compared 
the dentition of our form with that described and figured by 
Lehmann (Lebenden Schnecken, 132, pl. XIII., fig. 44), and find 
them to agree. I must, therefore, disagree with the decision of 
Morse (Journ. Portl. Soc.). I have also examined the genitalia 
of our species, and found it to agree with Lehmann’s figure (1. c.), 
especially in the existence of the very peculiar flagellum to the 
penis sac. This, however, cannot be considered as a most reliable 
specific character peculiar to this species, as it exists also in Cecz 
lianella acicula. 
I am very confident of the presence of well-developed side cusps 
to the central teeth, which Morse (1. c.) does not figure, though 
they are figured by Thomson, Ann. Mag. N. H., VII., pl. IV., fig. 
8. They appear to me also to bear the short cutting points which 
I have figured. 
Genus CHCILIANELLA, Bourg. 
I have not been able to examine the jaw or dentition of C. aci- 
cula (Cionella acicula of L. and Frw. Shells, I. 227), the only 
species found in our limits. They are both well known, however, 
from the descriptions and figures of Moquin-Tandon, Thomson, 
Sordelli,, and Lehmann. The jaw is low, wide, arcuate, with deli- 
cate vertical striz. The lingual membrane (Lehmann, Lebenden 
Schnecken, p. 128, pl. XIII, fig. 43) has 120 rows of 11—1—11 
teeth each. The centrals are small, tricuspid (Sordelli), the 
laterals, six in number, are larger, and have a more highly devel- 
oped reflection, and are also distinctly tricuspid. Marginals sub- 
quadrate, with a broad reflection, bearing delicate denticles. 
1 Sordelli (Atti della Soc. Italiana di Sc. Nat. XIII., fasc. 1, p. 50, pl. i. 
f. 25) describes the ribs to be not straight, but curving, with a median point 
projecting toward the end of the jaw, so that each rib resembles quite ex- 
actly the sign called ‘‘ brace’’ by printers. 
