DALL: MOLLUSCA AND BRACHIOPODA. 293 
periphery, where they form angular projections, obsolete on the last half of the 
last whorl, becoming obsolete midway between the periphery and the canal; 
the upper surface of the whorls flattish, sloping, with about fifteen fine, close, more 
or less alternated spiral threads; periphery with a strong projecting spiral keel 
more or less angulated by the ribs at their intersections; in front of the keel are 
about fifteen primary spiral ridges, low, with wider interspaces ; both the ridges and 
the interspaces sculptured with finer subequal close secondary threads, except on 
the canal where they alternate; aperture elongate, angulated by the keel; anal 
suleus wide, shallow ; outer lip sharp, thin, crenulated by the spiral sculpture; 
body with a thin wash of callus; pillar straight, obliquely truncate in front ; 
canal moderately long, rather wide and slightly flaring at the end; operculum 
none. Lon. of shell, 11.5; of last whorl, 8.0; of aperture, 6.2; max. diam. 
6.5 mm. 
U.S. 5S. “ Albatross,” station 3393, Gulf of Panama, in 1020 fathoms, mud, 
bottom temperature 36°.8 F. U.S. N. Mus. 123,130. 
The shell is probably not fully grown, and the character of the aperture may 
be somewhat different at maturity. 
Clinura peruviana Da tt, n. sp. 
Plate 13, figure 2. 
Shell small, white, with a thin grayish periostracum and about five similarly 
sculptured whorls exclusive of the (lost) nucleus; axial sculpture of (on the last 
whorl thirteen) sharp, narrow, vertical ribs, feeble and concavely excavated be- 
tween the suture and the keeled shoulder of the whorl, there prominently angular, 
beyond the shoulder vertical, becoming obsolete on the base; beside this the in- 
cremental lines are minutely elevated and rasp-like over the whole surface, but 
most so between the spirals; suture distinct, not appressed, the whorl between 
it and the shoulder descending and flattened, with five or six revolving fine 
threads and some secondary, finer intercalary threads; shoulder with a prominent, 
small, rounded keel, undulated by the ribs, beyond which similar spiral threads to 
the number of a dozen or more, with wider interspaces, to the canal; the first in- 
terspace has three equal fine intercalary threads, the second two, and the remain- 
der one each, becoming gradually closer anteriorly; aperture rather narrow, the 
anal sulcus wide, shallow, extending from the shoulder to the suture; aperture 
angulated by the shoulder keel; outer lip thin, entire; body with a wash of cal- 
lus, white, polished; pillar rapidly attenuated, straight, axis not pervious; canal 
narrow, straight. Lion. of shell, 9.0; of aperture, 5.2; of last whorl, 7.0; max. 
diam. 4.2 mm. 
U.S. 8. “ Albatross,” station. 4654, 24 miles N. 68° W. from Point Aguja, 
Peru, in 1036 fathoms, mud, bottom temperature 37°.3 F. U. S. N. Mus. 
110,564. 
