8 Proceedings of the Biological Society of Washington. 



on the spire only three cords are visible, the anterior more or less undu- 

 lated; on the base are a single cord, a wide interval, then three more 

 adjacent smaller plain cords, then three close-set beaded cords at the 

 verge of the small perforate umbilicus; aperture circular, upper lip pro- 

 duced on the body, the interior pearly white; breadth of shell, 6.2; 

 height, 5.5 mm. 



Habitat. — Taboga Island, Bay of Panama, James Zetek. U. S. Nat. 

 Mus. Cat. No. 331,837. 



Another specimen, long in the collection from Panama, but with no 

 collector's name, has all the spiral sculpture strongly beaded, and may 

 be called variety litharia. I have no doubt it is an extreme variety of 

 the same species. 



Liotia (Arene) cookeana, new species. 



Shell small, white, depressed, with a narrow crenulated suture and 

 three rapidly enlarging stellate whorls; axial sculpture of (on the last 

 whorl 13) prominent narrow ribs with wider interspaces, acutely pro- 

 duced at the periphery, and extending nearly to the crenate margin of 

 the funiculate umbilicus ; the whole surface in addition is covered with 

 fine close-set sharp almost microscopic axial threads ; beyond the peri- 

 phery are four or five spiral cords which do not appear on the ribs; 

 aperture circular, the margin crenated by the sculpture. Breadth of 

 shell, 3.0; height, 1.0 mm. 



Habitat. — In 7 to 10 fathoms off South Coronado Island, Dr. Fred 

 Baker. U. S. Nat. Mus. Cat. No. 223,290. 



This species may attain a larger size but none is known in the California 

 fauna of which it might be the young. It is named in honor of Miss 

 J. M. Cooke of Point Loma, Cal., to whom we are indebted for many 

 interesting shells. 



Liotia acuticostata, new var. radiata. 



Shell resembling the type but with numerous radiating riblets visible 

 in the interspaces between the revolving costae. 



Habitat.— OS South Coronado Island in 7 to 10 fathoms, Dr. Fred 

 Baker. U. S. Nat. Mus. Cat. No. 223,291. Also off San Diego in 20 

 fathoms. 



Liotia acuticostata, new var. stearnsii. 



Resembling acuticostata but smaller, with more numerous and less 

 prominent spiral cords. Height, 2.3; width, 2.3 mm. 



Habitat.— Gulf of California, Stearns. U. S. Nat. Mus. Cat. No. 

 47,062. 



