THE NAUTILUS. 91 
lamellze crossing the interspaces transversely but fading out on the 
ridges ; head-valve with minutely nodulous concentric ridges; tail- 
valve highest at the subcentral, not very prominent mucro, in front 
sculptured like the intermediate valves, behind the mucro like the 
head-valve. Length about i4, width 5°75, height 25 mm., in the 
dry state. The dry girdle about half a millimeter wide. 
Specimens obtained by Mr. T. S. Oldroyd from a stone pulled up 
from about 75 fathoms in the Santa Barbara Channel off San Pedro, 
California. 
This species, for which a section named in honor of Mr. Oldroyd 
is proposed, is very remarkable. The girdle recalls that of Deshayes- 
iella Carpenter, but is extended in such a manner as to partly sep- 
arate the shelly portions of the valves. The very callous surfaces of 
the interior, according to Mr. Pilsbry, are unique in the group. 
Most of the species of Lepidopleurus are comparatively thin, and 
though L. cajetanus is a solid shell, none of the species are as heavy 
as the present one in proportion to their size. The conspicuous and 
forwardly produced jugum is unique in the family. The type is in 
the National Museum, and will be figured later. 
PATELLA (HELCIONISCUS) NIGRISQUAMATA REEVE. 
BY CHAS. T. SIMPSON. 
In the collection of the National Museum are twenty specimens 
of Patella bearing the above name received from Frederick Stearns, 
the U. S. Exploring Expedition, W. K. Fischer, and the Lea- 
Chamberlain Collection—the latter credited to “ Dr. R.” by Mr. 
Lea, and probably from Ruschenberger. One other specimen of the 
same name is in the museum from the Rich Collection without lo- 
cality. 
These vary from young shells less than an inch in diameter to 
those which are more than 3) inches in length. There can be no 
doubt that the above name is correct, as all the specimens agree 
fairly well with Reeves’ description and excellent figures in the 
Cohchologia Iconica (Vol. VIII, Patella, species 3, plate II, figs. 
3* and 3°). 
The species described as P. boninensis in the Nauritus (Nov., 
1891, p. 79), was characterized by its author as having a large cen- 
tral muscular callus, and two diverging dark bands from the an- 
erior head segment. 
