187 



verging, the columellar shortly subreflexed. Alt. 1.2, diam. 3 

 mm." — Pilsbry, Phila Acad pr 1889:412. 



Type locality: — Mariposa Big Trees, Cal. (Hemphill). 



See Zonitoides selenitoides. 



2885 Mopalia heathii Pilsbry. 



"Oblong, rather elevated, carinated, with nearly straight side 

 slopes; surface smoothish to the naked eye, lusterless, and in 

 color (1) olive-green with some lighter spots, or purplish macula- 

 tion, or slight roseate suffusion, or (2) vivid red, with scattered 

 blue spots. Valves shaped as in M. lignosa, but without a me- 

 dian anterior projection of the tegmentum; the intermediate 

 valves very faintly radially trisulcate at the sides, the anterior 

 2 grooves defining the low, slight and inconspicuous diagonal rib, 

 the lateral areas not raised; entire surface very finely and evenly 

 granulate, the granules small, rather pointed, separated, intervals 

 very minutely, radially wrinkle-granulate. Anterior valve with 

 a few faint, shallow radial furrows. Posterior valve with semi- 

 circular posterior outline, the mucro in front of the middle of 

 tegmentum, profile of the surface in front of it convex, that of the 

 posterior slope decidedly concave. Interior deep rose color or 

 slightly purplish ; sutural laminss and sinus about as in lignosa. 

 Teeth rather long and somewhat roughened, as in lignosa. Valve 

 i with 8 slits; ii-vii with 1-1; valve viii entirely "Ischnoid," with 

 regular, crescentic insertion plate, cut by 7 or 8 slits, which are 

 somewhat closer posteriorly; no sinus behind. Girdle leathery, 

 nude except for solitary or 2 or 3 closely grouped long bristles at 

 all or part of the sutures, 1 on each side of the head valve, and 2 

 behind the tail valve. Gills about 25 on each side, not extending 

 quite to the anterior end of the foot. Length 25, width 12 mm. 

 (dried specimen), or smaller." — Pilsbry, Phila. acad pr 1898:288. 



Type locality: — Pacific Grove, Cal. (Heath). 



2886 Nuttallina Thomasi Pilsbry. 



Type locality:- — Pacific Grove, Cal. (Thomas). 



"General form oblong, rather depressed, not keeled dorsally; 

 surface granulose when not eroded. Color blackish or dark 

 brown, with a whitish band on each side of the median line of 

 back, or irregular whitish maculation; girdle dark. Intermedi- 

 ate valves short and wide, with a slight or hardly noticeable de- 

 pression on each side of the jugum, and others in front of and be- 

 hind the scarcely defined, obsolete, diagonal convexity; the ante- 

 rior and posterior margins subparallel, slightly arcuate. Ante- 

 rior valve granulate, without radial ribs, the posterior margin ex- 

 cavated mesially. Posterior valve with tegmentum slightly wider 

 than the anterior, the obtuse mucro somewhat behind the middle. 

 Interior blue-green, with the area behind the valve-callus dark 

 brown, or livid purplish, with light sutural lamina? and blue-green 

 area behind the sinus. Slits in valve i, 9 or 10; valves ii to vii, 

 1-1; valve viii, 10 or 11. Teeth rather separated, those of valve I 

 unequal, slightly rugose outside; posterior tooth of valves ii to vii 

 small, very obliquely directed forward; teeth of valve viii very 

 short, strongly directed forward and roughened. Sinus wide and 

 square, spongy, the area behind it transversely grooved. Eaves 

 rather wide, "spongy" or porous. Girdle sparsely covered with 

 short, rigid, obtuse, glossy spines of a blackish-brown color, or 

 occasionally some are whitish. Gills in type specimen, 26 on left, 

 23 on right side; not quite reaching the anterior end of the foot. 

 In another there are 23 on left, 25 on right side. Length 15,. 

 breadth 8 mm. or smaller." — Pilsbry, 1. c. 289. 



