121 



Perissolax brevirostris, Gabb. 



Ferissolax brevirostris, Gabb. — Pal. Cal., Vol. I., p. 91, pi. 18, fig. 43. 



Sucia Islands, in Division A.; J. Richardson, 1874. One nearly adult 

 and four or five immature specimens. 



LiTTORINA COMPACTA, GrABB. 



f Littorina compacta, Gabb.— Pal. Cal., Vol. I., p. 131, pi. 20, fig. 89. 



Lower Shales, or Division B, of the south-west side of Denman Island; 

 J. Eichardson, 1871. Two perfect but small individuals. 



Although no vestiges of any nacreous structure are apparent in the 

 above named shells, yet, in the writer's judgment, their general appeai-- 

 ance, thin test, and close resemblance to Photinula, suggest affinities 

 with the Trochidce rather than with the Littorinidce. If the words 

 " surface smooth" in Mr. Gabb's definition of the genus Ataphrus, were 

 altered to "surface smooth or spirally grooved," the name of the present 

 species could probably be better written Ataphrus compactus. 



POTAMIDES TENUIS, GaBB. 

 Plate 15, figures 8, 8a and 8i. 

 Fotamides tenuis, Gabb.— Pal. Cal., Vol. I., p. 130, pi. 20, fig. 86. 



Middle Shales, Division D, north-west side of Denman Island, two 

 nearly perfect and well preserved individuals. Lower Shales, Division 

 B, sotith-west side of Denman Island, two small examples. Sucia Islands, 

 in Division A., one very small and partly exfoliated specimen. J. Rich- 

 ardson, 1871-74. 



In the description of this species no mention is made of the fine 

 reticulation of the sm-face, so that ii is to be presumed that Mr. Gabb's 

 types did not show that character. In addition to the distant, elevated 

 nodules on the angles of the whorls, the exterior of the test of P. tenuis, 

 when in fine condition, is covered by a minute network, composed of 

 crowded revolving striations, which are crossed by equally fine, ti'ans- 

 verse, flexuous striae. A figure of the best specimen collected by Mr. 

 Eichardson has been given, as that in t^e Paleontology of California 

 does not give a very good idea of the shape or sculpture of the species. 



PoTAMiDES TENUIS, variety Nanaimoensis. 

 Plate 15, figures 9 and 9a. 

 Shell turreted, very long and slender; whorls nine, increasing very 

 gradually in size. The first five are convex, but somewhat compressed 



