ball: mollusca and brachiopoda. 283 



or tlie periphery on the last whorl ; spiral sculpture confined to the whorl in front 

 of the fascicle and consisting of (on the penultimate whorl about fifteen) fine, sharp 

 incised lines, oa the body of the whorl rather distant, the interspaces flat and often 

 unequal but toward tlie canal closer and more regular ; aperture semilunar ; anal 

 sulcus near the suture, wide, shallow ; outer lip very thin, sharp, simple ; body 

 polished ; pillar straight, gyrate, obliquely truncate in front; axis pervious; canal 

 short, wide, in front slightly flaring. Lou. of shell, 41 ; of last whorl, 24 ; of 

 aperture, 16; max. diani. 13.5 mm. 



U. S. S. "Albatross," station 3376, off the coast of Ecuador in 1132 fathoms, 

 ooze, bottom temperature 36° F. U. S. N. Mus. 123,135. 



Pleurotomella (Pleurotomella) sp. indet. 



A species of this group, but with the exterior so eroded as to be unrecogniz- 

 able, though apparently dilTerent from any heretofore mentioned, was obtained 

 East of Mapelo Island, in the Gulf of Panama, at station 3381, in 1772 fathoms, 

 mud, bottom temperature 35°. 8 F., and at station 3418, off Acapulco, Mexico, 

 in 660 fathoms, sand, temperature 39°. U. S. N. Mus. 123,124. 



Pleurotomella (Phymorhynchus) argeta Dall. 



Plate 19, figure 8. 

 Pleurotomella argeta Dall, Proc. U. S. Nat. Mus., 1880, 12, p. 307, pi. 6, fig. 5. 



U. S. S. " Albatross," station 2807, near the Galapagos Islands, in 812 fathoms, 

 mud, bottom temperature 38°.4 F. U. S. N. Mus. 96,552. Also at station 

 3407, in 885 fathoms, ooze, temperature 37°.2 F. U. S. N. Mus. 123.138. 



Though snow-white and perfectly smooth, except for incremental lines, this 

 species by the characters of the animal belongs with the brown spirally sculp- 

 tured forms which follow. 



Pleurotomella (Phymorhynchus) cingulata Dall. 



Plate 10, flKiiro 0. 

 Pleurotomella cingulata Dall, Proc. U. S. Nat. Mus., 1889, 12, p. 306, pi. 6, fig. 2. 



U. S. S. "Albatross," station 2793. off the coast of Ecuador, in 741 fathoms, 

 mud, bottom temperature 3S°.4. Also at station 2807, near the Galapagos Islands, 

 in 812 fathoms, mud, same temperature. U. S. N. Mus. 96, 554. 



This very handsome species is fully described and figured in the publication 

 referred to above. 



