DALL: MOLLUSCA AND BRACHIOPODA. 267 
- come less prominently sculptured and the ribs almost obsolete; aperture and 
canal short and wide; pillar with little callus, straight, solid; outer lip produced, 
thin, sharp, simple; anal sulcus wide, shallow, in the older shells nearly reaching 
the suture. Length of shell, about 18+; of last whorl, 11.5; of aperture, 8.0; 
max. diam. 7.0 mm. A 
U.S. 8. “Albatross,” station 3360, Gulf of Panama, in 1672 fathoms, sand; 
bottom temperature 42° F. U.S. N. Mus. 123,091. 
This species when old and eroded can hardly be distinguished from G. esuriens 
in the same condition, but fortunately specimens of the young shells in good con- 
dition could be compared and show obvious and sufficient characters proving the 
distinctions between the two species. 
Gemmula benthima Datt, n. sp. 
Plate 1, figure 7; Plate 13, figure 4. 
Shell solid, with a conspicuous greenish-gray periostracum, ten-whorled, with the 
spire longer than the aperture, biconic, usually much eroded; nucleus lost in all the 
specimens ; subsequent whorls appressed at the suture, in front of which is a strap- 
like revolving ridge with (on the fifth whorl twenty-two) low nodules, each one cor- 
responding to a feeble, strongly retractive, lamella-like riblet, which becomes prom- 
iment again as a semilunate nodule on the anal fasciole which forms the periphery 
of the whorl; between the fasciole and the presutural band the whorl is a little 
excavated; on the anterior side of the fasciole the whorl is rounded, with more or 
less alternated low spiral threads stronger near the periphery, where the suture is 
laid on the second thread, and diminishing toward the canal; the interspaces are 
decidedly wider than the threads, which become more or. less obsolete on the last 
whorl; the surface is also more or less reticulated by fine spiral striae and ele- 
vated lines of growth, giving it a rough aspect; last whorl much the largest ; the 
anal fasciole situated a little above the normal periphery of the whorl, but by its 
own prominent sculpture becoming peripheral; the sulcus is narrow and square- 
cut; outer lip thin, simple; body with a white callus which extends forward upon 
the very short, obliquely truncate but not pervious pillar, which is slightly re- 
curved ; operculum normal, large, brownish. Lon. of shell, about 28 + (decollate) ; 
of aperture, 14; max. diam., 12 mm. 
U.S. 8S. ‘ Albatross,” station 3392, off the Gulf of Panama in 1270 fathoms on 
hard bottom, temperature 36°.4 F. U.S. N. Mus. 123,089. Also at stations 
2807, 3360, 3365, 3366, 3376 and 3413, in from 812 to 1360 fathoms, sand or 
ooze, temperatures 36° to 42° F. in the Gulf of Panama, the adjacent coast of 
Ecuador, and the Galapagos Islands. 
This species is a typical Gemmula, with a narrow anal sulcus situated in the 
peripheral carina, an oval operculum with apical nucleus and concentric lines of 
increase, and nodose periphery. It is usually badly eroded. 
