PANAMIC-PACIFIC PELECYPODA 175 



row and very inconspicuous; on each side of it the margin is pustulate for 

 a short distance; the outer surface is mostly dark purple, dull, minutely 

 corrugated and densely covered with small erect tubules of a dark reddish- 

 brown color, 2 to 4 mm., high and from Vi to 1 mm. in diameter. Only those 

 at the extreme margin communicate with the interior of the valve, and 

 these are fissured on the distal side. Those of the surface behind the margin 

 are completely tubular. The attached valve unknown. (Dall, 1914, in part). 



Range — ^Gulf of California to Panama. Mexico: Gulf of California 

 (type, USNM). Panama: Pedro Gonzalez Id. (Pearl Islands), J. P. E. 

 Morrison, USNM. 588453. 



Ostrea ( ) serra Dall 



Ostrea terra Dall, 1914, Nautilus, vol. 28, No. 1, p. 2. 



Similar to Ostrea frons Linne of the West Indies growing attached to 

 stems of Gorgonia, narrow, plicate, with flattish upper valve, deep lower 

 valve, green or purple on the outside, inside white. 



Rare and poorly known. 



Range — Lower California to Panama (according to Dall). Panama: 

 Bucaro. 



Specific names referred to Panamic oysters of uncertain status. 



Ostrea aequatorialis d'Orbigny, 1846, Voy. Am6r. Merld., p. 672. Unfigured. 



The original description is too brief and generalized to identify the 

 species. D'Orbigny's remark that it is found (parasitically) attached to 

 trees suggests 0. colmnbiensis Hanley, 1846, described the same year. Ex- 

 amination of the original specimens is needed. 



Ostrea cnmlngriana Dunker, 1847 



Recorded by Dall from the faunal province (range given as Lower 

 California to Panama) but without mention of any specific locality. The 

 origin of the shell described by Dunker and figured in the Beschreib. und 

 Abbild. (vol. 2, p. 81, pi. 1, figs. 1-4) was unknown. It is a large, strongly 

 plicate shell resembling 0. fischeri but with more rounded ribs. Its occur- 

 rence in the Panamic Province is questionable. 



Ostrea prismatic Gray. 1825 



Often identified with 0. iridescens and which it would predate in name. 

 The figure presented by Reeve shows a shell with a high, massive cardinal 

 area, and ligament quite unlike the usual development in 0. iridescens. 

 There are numerous fossil species which would fit this figure, but we have 

 seen nothing like it in the Recent Panamic fauna. 



Superfamily AII^OMIACEA 

 Family ANOMirDAE 



Shell large or small, generally irregular and distorted, attached by 

 close contact to various objects by means of a calcified byssal plug passing 



