298 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY. 
It may be well to recall here that the shell to which I originally gave the name 
of Volutilithes philippiana, which is an evident descendant of some of the Chilian 
and Patagonian Tertiary types, is now known to possess a membranous proto- 
conch, and was referred by me, together with its fossil allies, to a section of Adelo- 
melon under the name of Miomelon (Feb., 1907). Not aware of this fact, my 
friend, Dr. von Ihering of San Paulo, Brazil, in June of the same year, proposed 
for the same group of species the genus Proscaphella, with P. gracilior Ihering, 
as type. This is the Voluta gracilis of Philippi, not of Lamarck. While the 
sculpture of these species is rather characteristic, they are united with the Ter- 
tiary ancestors of the recent Adelomelon by somewhat intermediate gradations, 
and therefore I think that they can hardly be more than subgenerically separated 
from each other.? 
Excepting 4. stearnsii of Alaska, which perhaps reached American waters by 
ancestral emigration along the western shores of the Pacific, the most northerly 
species of Adelomelon is the following shell. 
Adelomelon benthalis Datu. 
Plate 5, figure 8. 
Scaphella benthalis Dall, Proc. U. S. Nat. Mus., 1896, 18, p. 13. 
Adelomelon benthalis Dall, Smithsonian Misc. Coll. Quarterly, Feb., 1907, 48, p. 357. 
Shell recalling A. magellanica, Sowerby, but stouter, with more rounded 
whorls, the aperture shorter and wider, with a broad flexure where the lip turns 
to meet the body whorl, while in 4. magellanica the posterior part of the aperture 
is pointed; the latter has two strong plaits on the pillar; 4. denthulis has three, 
all obsolete, the middle one most perceptible, and has a less marked canal and 
siphonal fasciole. The interior of the aperture is pale flesh color; the exterior 
seems to have been like that of 4. magellanica, but is almost entirely decorti- 
cated. It has five whorls beside the nucleus, and there isno operculum. Height, 
125; of the last whorl, 90; of the aperture, 70; width of the aperture, 35; of 
the (decorticated) shell, 60 mm. 
U.S. 8. ‘‘ Albatross,” station 3360, in 1672 fathoms, sand, in the Gulf of 
Panama, temperature at bottom 42° F. U.S. N. Mus. 122,998. 
At first sight one would be disposed to think that this specimen represented a 
northward extension by 3360 miles of one of the Magellanic species, but a more 
careful examination shows numerous points of difference. 
The whorls are more nearly tabulate in front of the suture, the whorls rounder, 
the spire more rapidly tapering and relatively longer. 
1 By the misplacement of some paragraphs in the paper above cited, the genus 
Zidona has been inserted in the text before, instead of after, the portion treating 
of Miomelon, op. cit., p. 8363-365. 
