50 THE NAUTILUS. 



deformity ; but many specimens taken without other forms or 

 variation preclude such conclusion. The species is more closely 

 comparable with P. guantanameims and P. prohoscidea than 

 with any other of the group ; but from these it is separable by 

 the revolving sculpture and the up-tilted carina. It is the only 

 carinated Zachrysia yet observed. 



THE ANATOMICAL STRUCTURE OF GONIDEA ANGULATA (LEA) 



BY A. E. ORTMANN. 



The specimens at hand belong to the var. haroldiana Dall 

 (Smithson. Misc. Coll. 50, 1908, p. 499; Hannibal, Proc. 

 Malacol. Soc. London 10, 1912, p. 127, pi. 6, f. 10 ; Simpson, 

 Descript. Cat. Nai., 1914, p. 466). They have been collected 

 by H. Hannibal in Coyote Creek, Milpitas, Sta. Clara Co., 

 California, partly on March 31, 1913, and partly in June, 1913. 

 Over two dozen were received, among them males, sterile and 

 gravid females. 



Anal and swpramud openings separated by a well-developed 

 mantle-connection, which is about f as long as the anal, and 

 about half as long as the supra-anal. Inner edge of anal with 

 fine papillae. Branchial opening separated from the anal by 

 the gill-diaphragm, its inner edge with large papillae ; branchial 

 well defined anteriorly by the sudden disappearance of the 

 papillae. 



Palpi subfalciform, tlieir posterior margins connected for 

 about the half of their length. 



Gills long and broad, the inner the broader. Outer gill 

 gradually narrowing in front, its anterior end at the highest 

 point of the line of attachment of the mantle, quite distant from 

 the palpi. Inner gill narrowing more suddenly, and its anter- 

 ior end about midway between palpi and anterior end of outer 

 gill or at two thirds of this distance, but there is always a space 

 behind the palpi. Outer lamina of outer gills entirely con- 

 nected with mantle. Inner lamina of inner gills free from 

 abdominal sac, except at its anterior end. Behind the foot, 

 the two inner laminae of the inner gills are connected. Thus 

 the gill-diaphragm is complete. 



