display faint radiating grooves on the prismatic layer of the flat valve, 

 as in Kennerlia. 



4. CLIDTOPHORA PUNCTATA, Conr. 



Thrs very rare species was only known in England by worn left 

 valves in the British Museum, and in Mr. Cuming's and Mr. Hanley's 

 collections. The first perfect specimens were dredged by Dr. J. G. 

 Cooper (Zoologist to the Californian State Survey) at San Pedro. 

 A young shell, sent by him to the Smithsonian Institution, displays 

 a dentition agreeing in the main with C. trilineata. In the flat 

 valve, the central and anterior teeth are close together and nearly 

 parallel ; the anterior short, nearly obsolete ; the middle long and 

 sharp, corresponding with the long, sharp tooth in the convex valve, 

 which points to the outside of the anterior scar, instead of to the 

 middle, as in G. trilineata. The (posterior) clavicle-tooth in the fiat 

 valve is longer than in the Eastern species, with the cartilage on it 

 for two-fifths of the length. In C. trilineata it lies by the side, nearly 

 the whole way. The posterior margin of the convex valve fits between 

 the clavicle and the margin of the fiat valve. The ossicle is remark- 

 ably long and thin. The punctures are extremely conspicuous even 

 in this young, transparent, and papyraceous specimen ; and, what is 

 more peculiar, the dried remains of the animal are covered with 

 minute pearl-shaped grains of shelly matter corresponding with them. 



4 a. CLIDIOPHORA DEPRESSA, Sby.,=Pandora d., Sp. Conch, f. 

 11, 12 ; Hani. Rec. Shells, p. 49. 



The "posterior" dilated side of Sowcrby is the " anterior'' of 

 Hanley. The species was constituted from a " very few specimens, 

 all of them much worn down, as if they had been used as ornaments." 

 The hinge therefore may not have been accurately observed. They 

 were part of the Humphrey collection, and perhaps from the Califor- 

 nian region. Judging from the shape (for no type has been disco- 

 vered), it may be identical with C. punctata, Conr. 



5. CLIDIOPHORA ACUTEDENTATA (vice C. B. Ad.). 



C. t. parum " elongata, ovata ; parte postica " hand rostruta, 

 latiortyobtusa; " margine dorsali " postico "subrecto; margins 

 ventrali rotundato" hand tumente ; parte antica curtiore ; 

 " umbombus sul&yaaltter subconvexis, itmbone dextro postice 

 anaulato": intus, v. convexa dente antico magno, acutissimo, 

 medio parvo, postico va'ido, maxime elongate ; v. planata den- 

 tibus antico et postico acutis ; ligamentojuxta dentemposticum 

 sito. 



"Long. 7, lat. -42, alt. '11 poll." 



Hab. in Panama : sp. unicum, postice fractum, legit C. B. Adams 

 deploratus : Museo Coll. Amherstiange : = Pandora cornuta (Old.), 

 C. B. Ad. Pan. Shells, no. 498, P.Z.S. 1863, p. 368. 



Prof. Adams's "appropriate name suggested by Dr. Gould " being 

 calculated to mislead, I have thought it necessary to change it. 



227 



