156 AMERICAN JOURNAL 



ribs toward the margin. Lon. *76, alt. *76, diam. # 22 in., width 

 of hinge line *34 in. Angle at the umbones, 100°. 



Animal with the mantle margin profusely furnished with lemon 

 yellow tentacular filaments, and on the upper side only with six 

 pairs of black ocelli ; inner smooth part of the mantle pencilled 

 with dark brown, especially on the inner side. Foot cylindrical, 

 terminating in a minute rounded knob ; inner edge furnished 

 with half a dozen small papillae. 



Body yellowish white, with a pointed sac filled with ova, occu- 

 pying the greater part of the cavity. Byssus minute ; liver 

 greenish, muscles large, consolidated. 



Habitat, One lower valve, North Harbor, Unga Island, six 

 fathoms mud. Dall, 1865. One larger living specimen, exactly 

 agreeing, Port Etches, Chugach Gulf. Dr. Minor, U. S. Rev. 

 steamer, Wyanda. 



This remarkable little species is apparently quite distinct from 

 any described Pecten. It is, at present, impossible for me even 

 to decide in which section of the genus it should be placed. 



It differs from the young of tenuicostatus, Mighels, (==31agel- 

 lanicus, Lam.) in its sculpture and internal ribs and more rounded 

 shape. P. gramlandicus is smooth and otherwise different. The 

 internal ribs differ from those of Pleuronectia in being nodulous, 

 the internal supports of the latter are wanting, and the auricles 

 are notched. The valves close perfectly. Altogether, this is a 

 very interesting species. 



BRACBIOPODA. 



TEREBRATULID^. 



1. Terebratula unguiculus, Cpr. Straits of Fuca to San 



Diego. 

 Perhaps this species will prove a Terebratidina. 



2. Waldlieimia Grayi, Dav. Monterey. 



3. Laqueus californicus (Koch), Dall. Catalina Id. 



4. Terebratella transversa, Sby. (= T. caurina, Gld.) Neah 



Bay to the Aleutian Islands. 



LINGULIDiE. 



6. G-Jottidia albida, Dall. Santa Barbara to San Diego. 



RHYNCHONELLIDtE. 



6. Rhynchonella ? two species, both differing from the psitta- 

 cea, and probably described from Japan. 



