NO. IO MOLLUSKS BARTSCH AND REHDER 3 



and strongly wrinkled, widening somewhat posteriorly and blunt at 

 both ends. The pleuropodia are rather short and well separated in 

 front, united posteriorly, forming a wall about the branchial cavity 

 and mantle about an inch high. The mantle covers the shell com- 

 pletely and has a minute pore in the center. The posterior edge of the 

 mantle is somewhat sinused on the right side, with a short erect fleshy 

 crest slightly anterior to the sinus. The genital pore is conspicuous, 

 slightly crescentic, situated a short distance in front and to the right 

 of the anterior edge of the mantle ; a marked genital groove runs 

 anteriorly from it to below the right buccal appendage. The shell is 

 large, thin, chitinous, concave, shieldshape, with a moderately large 

 shallow sinus at the top where the edge is slightly thickened and re- 

 flexed. A thin deciduous calcareous layer is present on the ventral 

 surface. 



The type, U.S.N.M. no. 472859. measures: Length, 165 mm.; 

 width, 90 mm. ; height, 85 mm. (This is, of course, an alcoholic 

 specimen slightly distorted in the process of preserving.) The shell 

 measures : Height, 76 mm. ; width, 57 mm. It was collected on the 

 east side of Cedros Island, Lower California, along the shore to the 

 north and south of the cannery. 



This species resembles the Peruvian species Aplysia nigra d'Or- 

 bigny in having the lateral lobes united posteriorly, though not to as 

 great an extent, and in the posterior edge of the mantle being sinused 

 and bearing a fleshy crest. All the species heretofore described from 

 North and Central America have the pleuropodia free behind, not 

 united. There is no tail visible in our specimen. 



CONUS ROOSEVELTI, n. sp. 



Plate 1, figs. 4, 7 



Shell small, spire broadly conic, moderately elevated, sides of the 

 main part slightly convex on the posterior two-thirds and slightly con- 

 cave on the anterior third. The spire is flesh-colored with dark spots 

 between the knobs. The body of the last whorl presents a complex 

 color scheme. The general ground color is bright, light chestnut 

 brown, with a pale, moderately broad, submedian zone. The low, 

 rather broad, spiral cords bear elongated low white tubercles, whose 

 long axis coincides with the spiral sculpture. Between these white tu- 

 bercles there is usually, but not always, a dark, more or less round, 

 chestnut brown spot. The interior of the outer lip is brilliant chestnut 

 brown with a yellowish zone below the posterior angle, and a yel- 

 lowish submedian band and a series of dark spots near the edge. 



