O12 | Bulletin American Museum of Natural History _ [Vol. LIIT 
San Antonio specimens 
Length, 14.3 mm.; height, 13.0 mm.; diameter, 11.7 mm.; young. 
oe RG Gs (7 (73 
14.0 12. - 9.7 
eee ae tee oes. erga 3S 
es OOO teen 80 " 15.2 
Pe On) To ‘a 16.0 
we OE) De ee (ote . 15.0 
oS Oa ee ies fs 14.0 
Specimens apparently adult vary a good deal in size and in the 
proportions of height to length. The longest examples would be taken 
for a distinct species were it not for numerous connecting links. The 
height varies from 60 to 78 per cent of the length in San Antonio 
examples. The very full beaks remain constant in all. 
I. tumida (von Martens), from the Loango coast, is closely similar, 
but it differs by the shorter pallial sinus, which barely reaches beyond 
the middle of the shell’s length. 
Iphigenia rostrata Roemer — 
Plate XXX, Figure 1-1b 
Iphigenia rostrata Ramer, 1869, in Martini and Chemnitz, ‘Syst. Conch. Cab.,’ 
X, 3, Donacide, p. 116, Pl. xx1, figs. 5-8 (type locality: Lagos on the Slave Coast); 
1870, Malak. Blatter, XVI, p. 154. DavutzmnBrre, 1912, Ann. Inst. Océanogr. 
Monaco, V, 3, p. 95 (Rotuna, French Guinea). : 
Banana: on a sandbank at the entrance of the creek which leads to 
Moanda (Lang and Chapin Coll.). 
The shell is the largest of the genus, thin but moderately strong, triangular 
with convex base, the beaks small, projecting but little, about median. The front part 
‘tapers to a rounded end; posterior part is narrower, somewhat rostrate and bluntly 
pointed at end. Externally the shell is obliquely truncate posteriorly, a little depressed 
in front of the posterior ridge. Surface nearly smooth, marked with weak growth 
lines and much weaker traces of radial strize, often hardly discernable. Covered with a 
somewhat dull light brownish-olive periostracum with lighter, dull buff concentric 
streaks. The interior is white, partly tinted with light violet. Median cardinal tooth 
in right valve is high, triangular, bifid and distinctly rugose. Lateral teeth are long, 
straight and extremely slender. In the left valve the two cardinals are high but thin, 
the anterior one bifid. The nymphs are well developed. The pallial sinus extends well 
past the middle of the shell’s length. 
Length, 62.0 mm.; height, 45.6 mm.; diameter, 26.0 mm. 
nie ODIO a! 48.0 . 28.4 
; Wea ONY mo ALO a 26.0 
