100 PROCEEDINGS OF THE CALIFORNIA 



Subgenus 3IENETUS H. & A. Ad. Shell small, flat above, periph- 

 ery, and sometimes the base, angled. 



38 opercularis Gld: Wh. 4, rhomboidal in section, upper angle obtuse, 

 with 1 or 2 sub-marginal impressed Hnes, utnbil. sub-angled ; diam. *0.25-0.33, 

 height *0.06. 



Var. ? planulatus Cp. Higher, rounded below, whorls semilunar in sec- 

 tion, no impressed lines ; diam. *0.25, alt. *0.10. b. 



Subfam. Latiiim. Shell cryptiforra. with an upper chamber, and 

 a septum dividing the two. 



Genus GUNDLACHIA Pfeiff. Shell sinistral, sub-patelliform, apex 

 posterior, slightly twisted to the left, projecting as an obtuse spur 

 beyond the margin, and nearly separated from the main shell by an 

 internarSat septum, with a semilunar opening in front (in adult). 



39 californica Rwl. Outline sub-oval, widest anteriorly; diam. *0.08, 

 long. *0.16, alt. *0.06. 



Subfam. AncyUim. Shell patelliform, simple, conical. 

 Genus ANCYLUS Geoff. Shell dextral, shallow, mouth very wide, 

 apex a little to the right, not prolonged backward. 

 1 1 Apex about one-third the distance from the posterior end. 

 Q 40 crassus Hald. Outline oval, surface obtusely rounded, breadth 

 over .75, height .38 of length : long. *0.32, lat. *0.25, alt. 0.12. 



QVar. ? Kootaniensis Baird. Posterior slope concave, height .19 of 

 length; long. *0.2.5, lat. 0.18, alt. 0.05. 



41 caurinus Cp. Outline elliptical, sides parallel, ajjex acute, posterior 

 slope slightly concave, breadth half, height a third of length ; long. 0.25, lat. 

 0.12, alt. 0.08. 



Var. ? fnigilis Tryon. Apex a little more posterior, lower, narrower, an- 

 teriorly wider ; long. *0.16, lat. *0.04, alt. *0-04. (Description prior.) 



§ 2. Apex nearly central. 



42 patelloides Lea. Outline elliptic-oval, surface obtusely rounded, ray- 

 striped, breadth tftree-quarters, height half of length ; long. *0.33, lat. *0.25, 

 alt. *0.16. 



Q. Var. alius Tryon. Outline broad-oval, obtuse conic, one end nar- 

 rower ; long. *0.32, lat. 0.24, alt. 0.16. 



Q? Var. Newberryi Lea. Unicolor, height not half of length; long. 

 *0.55-0.70, lat. *0.40-0.50, alt. *0.20-0.30. 



Q? Var. subrotundatus Tryon. Outline nearly circular, breadth over 

 .75, height not half of length ; long. *0.32, lat. *0.26, alt. *0.12. 



Subgenus ACRULOXUS Beck. Apex directed to the left. 

 Q. 43 N u 1 1 a Hi Hald. Apex a fourth of length from end, breadth nearly 

 equal to, height over a third of length ; long. *0.32, lat. 0.30, alt. 0.12. 



b. This and Uo. 41 were mentioned without sufficient description in my Nat. Hist, of Washing- 

 ton Terr, etc., 18.59, and I am responsible tor the omission, as my father had left them in his M.SS. 

 report without specific names, which I supplied in tlie proofs. 



