OF CONCHOLOGY. 157 



Genus GLOTTIDIA, Dall. 



Shell linguiform, elongate, pedunculated ; general ch;n-acters 

 as, in Lingula. Neural valve provided internally with two sharp 

 narrow incurved laininaa, diverging from the beak and extending 

 about one third the length of the shell ; anterior extremities of 

 the laminae about midway between the mesial line and the mar- 

 gin. Haemal valve with a mesial septum of about the same 

 length extending forward from the beak. Anterior adductor 

 impressions rounded, separated by a faint mesial ridge, faintly 

 impressed. Scar of the post adductor close in the cavity of the 

 beak, rounded. No other evident scars. Shell smooth, perfo- 

 rate or imperforate. 



Type. G-lottidia albida, Dall. PI. 8, fig. 1 — 6. 



? Lingula albida, Hinds, Voy. Sulphur, p. 71, pi. 19, fig. 4. 

 Rve., Conch. Icon. pi. i, fig. 4. 



Ilab. San Diego, Cooper. Santa Barbara, 28 fms., New- 

 comb. Smithsonian Cabinet, No. 19,416. 



Shell creamy white. Smooth and polished except for faint 

 lines of growth, outside. Inside whitish toward the centre, yel- 

 lowish toward the edge ; extreme margin brownish horn color. 

 Interior with faint wrinkles, caused, perhaps, by drying ; longi- 

 tudinally faintly striate at the anterior margin. Mesial ridge 

 very faint, prolonged in a white line upon the yellowish part of 

 the shell near the anterior margin. Lamin?e sharp, elevated, 

 with their upper edges inclined inward, not blended in the beak 

 cavity, but continued, closely parallel, to the apex. They proba- 

 bly serve as fulcra for the post parietal muscles. They termi- 

 nate abruptly, not fading off gradually. Externally, toward the 

 anterior mairgin, there is a faint mesial ridge which terminates 

 in a small point on the anterior edge of the shell. Peduncle 

 stout, transversely wrinkled, exhibiting two, longitudinal ridges 

 with a deep groove between them. Length in the dried speci- 

 men about an inch. Neural valve -94 in. long by -48 in. wide 

 at the broadest part. Distance between the extremities of the 

 laminae -26 in. Height of the latter above the shell '02 in. 



A single neural valve with the peduncle attached and a frag- 

 ment of the haemal valve was recovered from some alcoholic mis- 

 cellanea received from Dr. Cooper, as dredged by him in San 

 Diego Bay, California. The fragments were returned by Mr. 

 Cuming as Lingula albida, Hds., and it is not improbably that 

 species. 



The specimen differs from the figure in the Conchologia 

 Iconica, in being more compressed at the sides, and in wanting 

 the oblique transverse striations of the figure. 



