1885.] PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 549 



Tellimya tumida Cpr. 



Sau Diego ; not found abundantly. 

 l»asea rubra Mout. 



Found in great numbers near high-water mark attached to the byssus 

 of Mytilus, in crevices, dead barnacles, and shells, or among small 

 stones. Also at Todos Santos Bay. 

 Kellia laperonsii Dosh. 



In dead shells or among rocks; not rare. 

 Chlamydoconcha orcutti Dall. 



lalse Bay, under stones. 



[I had intended to have subjoined a complete account, with figures, 

 of this singular form, but have been obliged to defer it on account of the 

 pressure of ofiicial duties. See Science, vol. iv. p. 50, July 18, 1884. D.J 

 Leda caslata Hds. 



Odd valves occasionally washed ashore. 

 Yoldia cooperi Gabb. 



A single valve found on the ocean beach north of False Bay. 



Area (Barbatia) gradata Sby. 



Abundant under stones at low water. 

 Cardita (Carditamera) subquadrata Cpr. 



With the above, but not common. 



Milneria minima Dall. PI. XXIV, figs. 5-7. 



Ceropsis minima Dall, Am. Jouru. Couch., vii, p. 152, pi. IG, figs. 5,6, 1871, 



(Generic name preoccupied.) 

 Milneria minima Dall, Am. Naturalist, Sept., 1881, p. 718. 



[This curious little member of the Carditidcc was discovered in 1866 

 by the writer and found nestling on the backs of Ecdiotis, which afford 

 a shelter for man,y small mollusks. The first specimens came from 

 Monterey; it was afterward found at Catalina Island, and Mr. Orcutt 

 now sends it from San Diego and Todos Santos Bay ; some specimens 

 from the last locality reacli 7.50"'™ in length and 0.00 in greatest 

 breadtn. 



Whde examining some dry specimens sent by Mr. Henry Hemphill 

 from San Diego some years since a very interesting feature was discov- 

 ered which may be briefly described as follows : 



Milneria is dioecious like most lamellibranchs, and there is quite a 

 difference in average size and proportional breadth, the male shell be- 

 ing always a little smaller and narrower than a female specimen of the 

 same length. Both attach themselves to surrounding objects by a 

 small byssus, for the passage of which a very slight gape exists be 

 tween the ventral edges of the valves. The ventral surface when the 

 valves are closed is nearly flat, an arrangement which has been brought 

 about by the needs of the creature settling like some Areas on a plane 

 surface like a flat stone or Haliotis back. The male has the base or 

 ventral surface a little striated. In the female, however, a much tuore 

 elaborate arrangement is found. We have in fact a proper marsupium. 



