284 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 
Pleurotomella (Phymorhynchus) castanea Datu. 
Plate 1, figure 1. 
Pleurotomella castanea Dall, Proc. U. S. Nat. Mus., 1895, 18, p. 15. 
Shell polished, thin, resembling P. cimgulata, Dall, of a chestnut-brown color, 
fading to a paler pinkish-brown, with seven whorls; the nucleus eroded, the early 
whorls with four or five flattened elevated spirals with wider interspaces in front 
of a somewhat sloping anal fasciole, more or less reticulated by narrow, slender, 
irregular, elevated riblets in harmony with the lines of growth, and which form 
on the fasciole delicate arches concave forward ; the suture is appressed; on the 
body are about twenty spirals, stronger at the shoulder, smaller and closer 
forward, the wide interspaces finely spirally striate, while the most prominent 
spirals are undulate or obscurely nodulous; the transverse sculpture is nearly 
obsolete and hardly to be distinguished from the incremental lines; aperture 
elongate, oval; outer lip thin, sharp, crenulated by the sculpture, but not lirate ; 
anal sulcus shallow, wide, directly in front of the suture; body with a thin wash 
of callus; pillar thin, gyrate, attenuated in front, forming a narrowly pervious 
axis, the whole of a pinkish-brown color; canal short, shallow, not recurved. 
Height of shell, 53; of last whorl, 38; of aperture, 28; diameter, 23 mm. 
U. 8S. S. “ Albatross,”’ station 3400, in 1322 fathoms, ooze, temperature 
36° F.; eastward from the Galapagos Islands. U.S. N. Mus. 123,134. 
This differs from P. cingulata Dall by its smaller size, more sloping whorls, 
more delicate and reticulate sculpture, and by its pervious axis. The animal is 
blind, and there is no operculum. ‘There is a distinct muzzle into which the 
proboscis is retracted when at rest, as described under Pleurotomella argeta in 1889, 
and at page 258 of this report. Specimens were also obtained at station 3374, 
Gulf of Panama, in 1823 fathoms, ooze, bottom temperature 36°.4; and at station 
3413, in 1360 fathoms, ooze, near the Galapagos Islands, temperature 36°F. 
Pleurotomella (Phymorhynchus) oceanica Datt, n. sp. 
Shell short, stout, white, the spire shorter than the aperture, including about 
six whorls; nucleus eroded, whorls rounded, but the shoulder rather posterior, 
giving a subtabulate aspect to the whorls ; suture distinct, not channelled; axial 
sculpture of fine, close, subequal lines in harmony with the lines of growth; 
spiral sculpture of numerous flat, longitudinally striated straplike slightly elevated 
bands, with subequal interspaces about half a millimeter wide, or less; there is a 
slight arcuation in the lines of growth but no anal fasciole; aperture pyriform, 
outer lip thin, simple, sharp, with no anal sulcus ; body with a thin wash of white 
callus; pillar short, twisted but not pervious, obliquely attenuated in front; 
canal hardly defined, wide, very short, slightly recurved; alt. 25; of last whorl, 
20; of aperture, 15; max. lat. 15 mm. 
U.S. S. “ Albatross,” station 3681, in Mid-Pacific, north latitude 28° 23/, 
