812 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 
ble; whorls moderately rounded, suture appressed; axial sculpture of, on the 
last whorl, about ten, inconspicuous vertical ribs, which bear, near the suture, 
a feeble spiral row, at the shoulder a very conspicuous row, and on the body 
of the last whorl three less conspicuous rows, of smooth, more or less orange- 
tinted, rounded, prominent nodules; between the spiral rows of nodules there are 
four or five equal and equidistant fine spiral striae; the surface of the shell is 
subtranslucent, recalling that of Purpura lapillus L.; aperture ovate, in the adult 
minutely channelled behind, glazed with a rich orange enamel, contracted sharply 
at the beginning of the canal; outer lip not reflected, thin-edged, with an internal 
thickening which is faintly lirate ; body with a broad layer of callus, of which the 
left hand or outer border is a little raised ; a small subsutural nodule in the adult 
and one on each side the entrance to the canal; pillar short, canal very short, 
deep, and strongly recurved, making a very prominent siphonal fasciole with 
a constriction behind it, and deep umbilical chink between it and the reflected 
edge of the columellar callus. Lon. of shell, 15.5; of last whorl, 10.0; of aper- 
ture and canal, 7.05 max. diam. 6.5 mm. 
Collected by the “ Albatross” party on the reefs at Easter Island. U. S. N. 
Mus. 110,767. 
This shell is not an Aspella, as it wants the peculiar chalky surface of that 
genus and has a totally different sculpture; but I am unable to suggest any 
group which seems more similar. 
The radula is most like that of Zrophon elathra'us as figured by Troschel, 
Gebiss der Schnecken, 2, pl. 11, figure 17, but differs in having the outer cusps 
of the rhachidian tooth nearer the outer ends of the basal plate, straighter, and the 
central cusp of the same tooth longer and more prominent. The laterals have 
also longer and stronger cusps, though of the same general shape. 
The upper surface of the mouth is covered by a thin, smooth layer of chitine, 
while the anterior margin of the layer is modified into an evenly arched thick- 
ened narrow ridge performing the office of a jaw, with the middle part sculptured 
with many minute spicules or projecting needle-like spines. 
The operculum is more or less lozenge-shaped, purpuroid, with a marginal 
coating of reddish brown enamel on the inner face. 
The tentacles were slender and small and the eyes present, though details 
could hardly be had since the data were obtained from a soaked-out specimen 
which had been dried in the shell. 
The shell is not a Trophon or Boreotrophon in the strict sense; in concholog- 
ical and opercular characters it differs from Aspella; it cannot be referred to 
Purpura (= Thais) or Murex, and I am therefore constrained to propose a new 
sectional name for it with the following characters : ; 
Shell small, with nodular seulpture; the aperture with a projeeting margin, 
feebly lirate within the outer lip when adult, constricted in front at the beginning 
of the canal; dentition like Boreotrophon ; operculum purpuroid, lozenge-shaped, 
with a raised border on the inside face; mouth provided with an arcuate chitinous 
jaw. 
