19 



182 Lunatia lewisii Gld 



Rare; apparently common in deep water and farther south. 



183 Sigaretus debilis Gld 



I have a single broken individual from San Diego, and another 

 from Todos Santos bay. 



184 Lamellaria diegoensis 



False bay at low water, April and May; rare. When living 

 the soft parts completely cover the shell and are, in part, of a 

 vivid red color similar to that of Doris sanguinea. 



[Soft parts as contracted in alcohol about .65 inch in length, 

 above smooth or nearly so, dull white or grayish, beneath lighter 

 colored; form rounded oval, a well-marked notch in the mantle 

 edge (notaeum) a little to the left of the middle line in front; 

 foot rather large, rounded behind, nearly transversely truncate 

 in front with rounded corners and the front margin deeply 

 grooved or double; head dark gray above, flattened; tentacles ob- 

 tusely tapering, somewhat flattened; eyes large and black, on 

 tubercles outside of the bases of the tentacles; mouth hidden un- 

 der the head, small; verge extremely large, broad, flattened, ex- 

 tending forward beyond the head, curved to the left in a broad 

 ascending spiral; smooth below, granulous above with a short line 

 of elevated papillae inside the edge of the outer part; beyond the 

 curve is an indentation on the left side behind which is a stout 

 conical papilla from the apex of which extends upward a slowly 

 tapering cylindro-conic tubular portion; the nuchal cavity is pro- 

 longed backward under the anterior edge of the immersed shell; 

 shell calcareous except the immediate margins of the aperture, 

 grayish waxen white, slightly irridescent with a mucilaginous 

 polish like dry glue inside and out, somewhat malleated, with in- 

 dications of the lines of growth by obscure slightly elevated trans- 

 verse waves and faint irregular spiral tracings; three-whorled, 

 very much inflated, though the form varies slightly between indi- 

 viduals and probably between the sexes; nucleus small, smooth; 

 suture deep, not channeled; spire pervious from below; columella 

 less calcareous than the shell in general, without callus or any 

 thickening, twisted into an open spiral, continuous with the outer 

 lip in front only; aperture very oblique, subquadrate. Alt. 15; 

 max. lat., 17; long, of aperture, 12; lat. of aperture, 19 mm. 



This shell was first received from Mr. Henry Hemphill of San. 

 Diego; subsequently other specimens came to hand from Cape 

 St. Lucas. As will be seen from the characters of the soft parts, 

 it is a true Lamellaria (Marsenia, Leach, is a later and synony- 

 mous name). It is more inflated and elevated than any European 

 or West American form known to me. 



Lamellaria stearnsii Dall (1871) is a depressed and much 

 more calcareous species, which has the soft parts translucent 

 white, and the shell distinctly finely striated. Lamellaria rhom- 

 bica Dall proves to be a Marsenina, though the shell does not 

 greatly differ from that of L. stearnsii, and should take the name 

 of Marsenina rhombica. The two forms of L. stearnsii, one of 

 which was described as a variety orbiculata, may turn out to be 

 sexually distinct, as the differences are such as mark the two 

 sexes of the common British species according to Jeffrevs. Both 

 the just mentioned forms, as well as Marsenina rhombica, were 

 collected at Monterey; while L. diegoensis seems to belong to the 

 southern fauna. D.] 



