Geol— Vol. II.] ANDERSON— CRETACEOUS DEPOSITS. 89 



29. Hamites cylindraceus de France. 



Hamites cj/hidraceus {d'Orb.) de France, Pal. Franc, Vol. I, PI. CXXXVI. 

 ScHLUTER, Paleontographica, Vol. XXI, p. 103, PI. XXXI. ? not //. cyl- 

 indraceus (de France) Whiteaves, Canada Geol. Sur., Mes. Foss., 

 Vol. I, 1876-S4, p. 113, PI. XIV. 



Among the fossil cephalopods collected in Southern 

 Oregon is one that closely resembles //. cylindraceus, as 

 figured by Schlliter (1. c), belonging to the Upper Creta- 

 ceous of Europe. The suture line is not visible on any of 

 the specimens collected, but in their superficial features 

 they agree too nearly with the European species to justify 

 any other determination. 



Shell not large, nearly cylindrical in section; elongated in the later portion, 

 straightened and recurved into a hook-like bend with two parallel arms; sur- 

 face crossed by simple annular ribs which are usually oblique to the axis, 

 without nodes or noticeable irregularities, except in direction. Some of the 

 ribs show a tendency to arrange themselves in planes perpendicular to the 

 axis of the shell, but the inclination is generally forward on the siphonal side. 

 The ribs are narrow and ridge-like, and separated by furrows which are 

 rounded on the bottom and at least twice as wide as the ribs themselves. 

 The diameter of the body-chamber in the largest specimen obtained is about 

 1.7 centimeters. All the specimens lack the band-like constrictions seen on 

 the species described by Whiteaves from the Sucia Islands. 



30. Hamites armatus, sp. nov. 



Plate V, Figs. 130-132. 



Shell of medium size, attaining a greater diameter of about 20 mm.; ellip- 

 tical in cross-section; surface ornamented with regular rounded ribs inclining 

 obliquely forward; body- whorl crossed by strong constrictions about 30 mm. 

 apart, between which there are about twelve or thirteen parallel ribs; every 

 fifth or sixth rib armed near the siphonal line with two widely diverging 

 spines, attaining a length of 6 or 7 mm. ; the intervening ribs also armed but 

 with shorter spines. The area between each pair of longer spines is some- 

 what flattened, and marked by a narrow oval, especially when two of the 

 ribs coalesce to form the spine-like tubercles. The septum of this extra- 

 ordinary species is not yet known, but it is probably sufficiently well 

 characterized. 



Occurrence. — This shell was found in the Lower Chico 

 beds near Henley, Siskiyou County, California. It was 

 found associated with Pachydiscus henleyensis, Desmoceras 



