184 
MARINE SHELLS OF WEST COAST OF NORTH AMERICA 
Donax conradi Deshayes, 1854. 
Proc. Zool. Soc. 1854, p. 351. Conch. I conic a, 8; pi. 5, fig. 29. 
D. testa elongato-transversa, subtrigona, solidula, compressa, inaequi- 
laterali, radiatim tenue striata, grisea, fusco dilute picta, postice viola- 
scente, aliquantisper albo-grisea vel rufescente, striis impressis in medio 
simplibus, antice posticeque punctatis; umbonibus minimis, albis, violaceo 
breviter biradiatis; latere antico elongato, attenuato, cuneformi, superne 
recto, declivi, postico oblique truncato, obtuso, inferne subangulato, striis 
multo tenuioribus; lunula elongato-lanceolata, angusta, impressa, violacea, 
angulo marginata; valvis intus violaceis; cardine albo; sinu pallii elongato, 
horizontali, obtuso, marginibus parallelis; marginibus tenue crenulatis. 
(Deshayes.) 
Shell elongately ovate, rather gibbous, compressed at the margin, 
smooth, radiately closely grooved, grooves linear, the posterior, inter¬ 
mediate ridges minutely serrated; whitish, ash-banded; umbos purple, 
white-tipped; lunule and posterior area ash-purple, anterior side elongately 
rounded, posterior rather concavely truncated. (Conch. Iconica.) 
Type in Mus. Cuming. Type locality, Gulf of California. 
Range. San Diego, California, Central America. 
Family PSAMMOBIIDyE. 
Genus PSAMMOBIA Lamarck, 1818. 
Shell elongated, more or less pointed behind; compressed; somewhat 
rudely, concentrically sculptured; the posterior dorsal area frequently 
sculptured diversely from the disk; pallial sinus elongated and for the 
most part coalescent below with the pallial line. Pal. San Pedro. (Arnold.) 
Type. Tellina ferroensis. Chemnitz. 
Distribution. Britain, India, New Zealand, Pacific west coast. 
Range in time. Cretaceous to Pleistocene. 
Subgenus Gobr^eus Leach, 1852. 
Psammobia regularis Carpenter, 1864. 
Ann. Mag. Nat. Hist. (3), 13:312. 
P. testa minore, regulariter ovali subsequilaterali; violacea, plus minusve 
radiata seu maculata; larvi, striolis incrementi ornata; epidermide tenui, 
flavido-olivacea induta, postice rugulosa; marginibus undique regulariter 
excurvatis; umbonibus vix projectis; ligamento conspicuo; intus dent, 
card. ii. —1., haud bifidis; cicatr. adduct, postica rotundata, antica ovali; 
sinu pallii elongato, haud incurvato, per duos trientes interstitii porrecto. 
Long., 1.05; lat., 0.05; alt., 0.26 poll. (Carpenter.) 
Type in U. S. N. M. Type locality, Cape San Lucas, Lower California. 
Range. San Diego, California, to Cape San Lucas, Lower California. 
