152 COLORADO FORMATION AND ITS INVERTEBRATE FAUNA, [bull. IOC 



Fusus (Neptunea?) venenatus n. sp. 



PI. xxxn, Figs. 1 and 2. 



Shell fusiform, rather large ; spire conical, equaling or exceeding 

 the aperture and canal in length; volutions about six, convex, ob- 

 liquely flattened above; last whorl abruptly contracted into the canal, 

 which is not complete in any of the specimens, but was evidently rather 

 short and bent to the left (in aperture view). 



Surface with numerous thread-like revolving lines and a row of 

 prominent rounded nodes, of which there are. about twelve on each 

 volution. In the shells with more elongate spires like the largest one 

 figured, this row of nodes is near the middle of the whorls of the spire, 

 while in those that are more depressed it is near the suture. The 

 nodes are not conspicuous on the earlier whorls. Aperture, exclusive 

 of canal, oval; inner lip with a moderately thick callus; outer lip un- 

 known. 



Length of largest specimen, exclusive of canal, 72 mm ; breadth, 43 ,nm . 



The collections from Huerfano park contain a large number of frag- 

 mentary specimens that I have placed in this species. They vary con- 

 siderably in form, the extreme being shown by the two specimens fig- 

 ured. These two would hardly be regarded as belonging to the same 

 species if it were not for the fact that other examples seem to be 

 exactly intermediate between them. 



In size and general appearance this species has some resemblance to 

 Fusus (Serrifusus) dakotensis M. & H., but the volutions are not at all 

 carinate, as in that species, and the form of the aperture is different. 



Locality and position. — In the Pugnellus sandstone on Williams 

 creek, in Poison canyon, and other localities in Huerfano park, Colorado. 



Genus TRITONIDEA Swainson. 



Tritonidea? huerfanensis n. sp. 



PI. xxxi, Fig. 15. 



Shell rather small, short fusiform, spire elevated, about equal in 

 length to the aperture and canal; whorls six, ventricose, abruptly 

 contracted just below the suture so that they have a shouldered appear- 

 ance, with prominent rounded nodes on the shoulder of the body- whorl. 

 On the spire these nodes are elongated into transverse costre that com- 

 pletely cross the exposed portion of the whorl. Surface also marked 

 by numerous flat revolving lines that are broader than the spaces 

 between them. Aperture not seen. 



Length of the type specimen, 23 mtn ; breadth, 14 ram . 



In general appearance this species is not very different from some of 

 the smaller individuals of Fusus (Neptunea?) venenatus with which it 



