NO. 12 STRONG AND HERTLEIN : MARINE MOLLUSKS 225 



Holotype: No. 709 (Calif. Acad. Sci. Paleo. Type Coll.), from 

 Loc. 27,228 (C.A.S.), dredged in from 3 to 9 fms. oE Taboga Island, 

 Panama. L. G. Hertlein collector. Fifteen additional specimens were 

 dredged at the same locality. 



The sculpture of this species is so different from that given in the 

 description of any other west coast species that any comparison would 

 seem to be of little value. 



This species is named for Ferdinand Freiherr von Richthofen, early 

 member of the California Academy of Sciences. 



Micranellum lohri Strong & Hertlein, new species 

 Plate 20, Figs. 12, 13 



Shell consisting of a moderately curved, slightly tapering, opaque, 

 white tube; sculptured with about 50 low, flattened rings separated by 

 narrow, squarish grooves; the anterior end of the tube slightly expanded, 

 the expanded area extending over a width of about 8 rings; the last 

 ring contracted, the face marked with 3 fine, incised, annular lines, 

 forming a narrow, rounded edge to the aperture; aperture circular, at 

 a slight angle to the curved axis o'f the tube, the last ring being nar- 

 rower on the concave than on the convex side of the tube; posterior 

 end closed by a plug encircled by a very narrow raised rim; the entire 

 surface of the plug rising toward the convex side of the tube and 

 ending in a triangular spur near the edge. Operculum concave, horn 

 colored, with a central nucleus and about 12 concentric rings. The type 

 measures: length, 4.4 mm; diameter of tube, 1.2 mm. 



Holotype: No. 732 (Calif. Acad. Sci. Paleo. Type Coll.), from Loc. 

 27,228 (C.A.S.), dredged in from 3 to 9 fms. ofi Taboga Island, 

 Panama. L. G. Hertlein collector. About 130 additional specimens 

 were dredged at the same locality. 



The size and shape of this species is quite similar to that of 

 Micranellum crehricinctum Carpenter,^*' from California, but that 

 species has about twice as many and much finer rings. In the younger 

 stages, shown on some of the paratypes, the rings are so faint that they 

 are only indicated under the microscope. However, the long, slender 

 form and triangular plug would seem to be sufficient to distinguish 

 this stage from any other description of a west coast species. 



50 Caecum crehricinctum Carpenter, Proc. Calif. Acad. Sci., vol. 3, February, 

 1866, p. 215. "Hah. San Diego, 8-10 fms., 12; Monterey, 20 fms., 20, some alive; 

 Santa Barbara, 20 fms., 3, Cooper." 



