DALL: MOLLUSCA AND BRACHIOPODA, A417 
Vesicomya ovalis Dat. 
Callocardia ovalis Dall, Proc. U. S. Nat. Mus., 1896, 18, p. 18. 
Shell resembling the V. Jepta Dall, but smaller, more oval, the posterior dorsal 
border more arched, the proportional inflation greater, the lunule wider, the liga- 
ment proportionally and actually longer, the epidermis more adherent and without 
projecting fringes or lamellae; internally the teeth are smaller and more feeble, 
and the pallial line recedes less at the posterior adductor scar. Height, 26; 
length, 36; diam. 16 mm.; the vertical of the beaks 8 mm. behind the anterior 
end of the shell. 
U.S. S. “Albatross,” station 3360, in the Gulf of Panama, in 1672 fathoms, 
sand; temperature 86°.4 F. U.S. N. Mus. 106,898. 
Vesicomya donacia Datt, n. sp. 
Plate 17, figures 9, 13. 
Shell swollen, cuneate, inequilateral, chalky white, covered with a pale oliva- 
ceous periostracum, finely concentrically striated; beaks high, inflated, markedly 
prosocoelous with a broadly cordate lunular space circumscribed by a strongly 
impressed line; ligament long, black, on a thin lamellar nymph ; anterior end 
rounded, attenuated, short; posterior end longer, attenuated, slightly arcuate 
and obscurely rostrate; hinge line and base subequally arcuate; hinge in the 
left valve with two undifferentiated cardinal teeth almost parallel with the hinge 
line above them, from which they are separated by a shallow, widely V-shaped 
socket for the tooth of the right valve; under the nymph, and of about equal 
length, the hinge line shows an elongated narrow ridge, simulating a pseudolateral 
tooth; interior dull white, yellowish in the middle of the disk; margins and 
pallial line entire; the muscular scars distinct. Lon. 22; alt. 16.5; semi-diam- 
eter (left valve), 7.0 mm. 
U. §. S. “Albatross,” station 3392, Gulf of Panama, in 1270 fathoms, hard 
bottom, temperature 36°.4 F. U.S. N. Mus. 122,929. 
Only one left valve was obtained, but the form is sufficiently unlike the other 
species to be readily recognizable. 
Vesicomya stearnsii Datt. 
Callocardia stearnsit Dall, Proc. U. S. Nat. Mus., 1895, 17, p. 698, figs. 1A, 1B; 
1896, 18, p. 17. 
U. 8. S. “Albatross,” station 3346, off Tillamook, Oregon, in 786 fathoms, 
mud, bottom temperature 37°.3 F. Also at station 3010, Gulf of California, in 
1005 fathoms, mud, temperature 37°.6 F. 
The species has much resemblance to V. venusta Dall, from the Atlantic, but 
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