1 6 Palabontographica Americana i6 



middle teeth vertical, small, or even obsolete mesially; margins of the valve slightly or 

 not at all crenulated by the sculpture. Length of shell 47, of hinge-line 30, height 31, 

 diameter 26 mm. 



"This species is very evenly and regularly fluted at the imbrications, differing in 

 that respect from any of the other species mentioned here. It is notable also for its in- 

 flated and thin valves and the bluntly truncate posterior end, though the latter may be 

 abnormal. — Dall. ' ' 



Occurrence. — Oligocene of the Ballast Point silex beds, Tampa Bay, Florida. — Dall. 



Area phalacra Dall 

 Plate III, Figure 10 



Barbatia {Calloarca) phalacra Dall, Wagner Free Inst. Sci., Trans., vol. 3, pt. 4, p. 6j6, pi. 33, 

 fig. 3, 1898. 



"Shell thin, moderately convex, equivalve, inequilateral ; the prosogyrate beaks 

 within the anterior fourth low and somewhat compressed; sculpture of very numerous 

 fine, even, mostly .dichotomous riblets without nodules or reticulation over the whole 

 shell, crossed only by feeble incremental Hnes; cardinal area very narrow, with a few 

 longitudinal grooves; hinge-teeth small, short, a:nd vertical mesially without any gap in 

 the series, distally longer, larger, and more oblique; hinge-line 0.6 of the whole length; 

 internal margin of the valves smooth, byssal gape inconspicuous. Lon. 23.5, alt. 11, 

 diam., 9 mm. 



"This is a very modest and neat little species which does not seem identifiable with 

 any of the others. It is, perhaps, nearest to B. ftiississippiensis Conrad, but is smaller, 

 less flattened, and more regular." — Dall, 1898. 



Cf«<yrfn<-f. ^Oligocene of the Chipola marls, Chipola River, and of the Oak Grove 

 sands, Florida. — Dall. 



Area eandida Gmelin 



Plate III, Figures 11, 12 



Area Candida Helblingi, Chemnitz, 7, p. 195, pi. 55. fig- 54^ 



Area Candida Gmelin, Syst. Nat., 6, p. 3311, 1792. 



Area Helblingii Bruguiere, Encyc. Meth., p 195, 1797. 



Area jatnaicensis Gmelin, Syst. Nat., 6, p. 3312, 1792. 



Barbatia (Calloarca) Candida Dall, Wagner Free Inst. Sci., Trans., vol. 3, pt. 4, p. 626, 1S98. 



"A. testa pellucida rhomboidali anterius producta posterius truncata decussatim 

 striata : natibus remotis, margine posterius hiante ; hiatu ovato ciliato. 



Chenin. Conch. 7. t. 55 f. 542. 



fi) Chemn. Conch. 7. t. 55. f. 544. 



Habitat in Oceano americano et aaf Africae littus occidentale, testa alba, quasi gran 11- 

 lata, epidermide villpsa ex atro subfusca obdueta." — Gmelin, 1792. 



The synonymy is taken from Dall, who says, "There are some difficulties in the 



