354 



It is possible, also, that the sp-^cimens collected by Mr. Richardson, at 

 Blunden Point, V.I., and at Hornby Island, that were doubtfully referred 

 to Bxdla Hornii, may rather be referable to Cylichna costata. Those 

 from Admiralty and the Sucia Islands, collected also by Mr. Richardson, 

 are, however, shorter and wider in proportion to their length, and these 

 are very similar to Bulla Hornii, as figured by Gabb, much more so than 

 figure y, on Plate 16, of the second part of this volume would leave one 

 to infer. It is not at all likely that Gabb's typical B. Hornii is a true 

 Bulla, as that genus is now restricted. The specimens from the Admi- 

 ralty and Sucia Islands that have been identified therewith may be refe- 

 rable to Cylichna rather than to Haminea, and may indeed prove to be 

 only a short and wide form of C. costata. 



CiNULIA OBLIQUA, Gabb. 



Cinulia obliqna, Gabb. 1864. Geol. Surv. Calif., Palseont., vol. i, p. Ill, pi. 19, figs. 

 64, and 64 a, b, c. 



Whiteaves. 1879. This volume, pt. 2, p. 1.31. 

 White. 1889. Bull. U.S. Geol. Surv., No. 51, p. 45. 



Specimens which are obviously referable to this common specie-^ were 

 collected at the Sucia Islands by Dr. Newcombe in 1894 and 1896; at 

 Brennan Creek, V.I., by the Rev. G. W. Taylor in 1901 ; and on the 

 Nanaimo River, two and a quarter to ten or twelve miles from its mouth, 

 by Mr. Harvey in 1901. 



Trochaot^on semicostatus. (N. Sp.) 



Plate 44, fig. 5. 

 Shell very small, narrowly subovate or ovately subcylindrical, fully 

 twice as long as wide, with a short, angularly step-shaped spire, and 

 narrowly rounded base. Spire composed of four volutions ; outer volution 

 shouldered above, widest at and for a short distance below the shoulder 

 and narrowing gradually into the narrowly rounded or somewhat pointed 

 base, or termination anteriorly. 



Surface marked with numerous minute and close-set ribs, that cross 

 the volutions transversely but become obsolete at the base of the outer 

 volution. These ribs can only be seen with the aid of a lens, and are 

 merely indicated in the figure. 



Roof of coal. New Vancouver Coal Co.'s mine, Nanaimo, V.I., W. 

 Harvey, 1901 : six fairly well preserved but imperfect or distorted 

 specimens, the largest of which is not quite six millimetres long. 



