854 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127 
Measurements in mm.— 
Visceral 
Brachial Hinge disk Trail 
Length length Midwidth width Height length length 
elbty pe fiance cai 15.3 ig 15.4 15.0 3.1 8.5 7.0 
Paratype (117660a)... 23.9 ? 30.4 26.2 3.0 9.5 15.0 
i (117660b)... ? 16.8 20.0? 26.0 22° A 10.4 
af (157658) 44 38 14.2 17.4 17.5 ? 9.2 5.3 
B (117659b)... 14.6 ? 16.3 12.8 2.8 8.5 6.5 
2 (G@aI7G50c)Aaea e 14.0 18.0 15.7 ? 8.5 5.5 
Types.—Holotype : 1176592 ; figured paratypes : 117658, 117659b,c, 117660a,b ; 
unfigured paratypes: 117659d-g. 
Horizon and locality—Rodman member of Nealmont formation in Pennsyl- 
vania: On the old road north of Roaring Spring, Hollidaysburg (15’) Quad- 
rangle; 65 feet below top on the Pennsylvania RR. 4 mile north of Roaring 
Spring, Hollidaysburg (15’) Quadrangle; 15 feet below the top in the west end 
of the quarry at Salona, Lock Haven (15’) Quadrangle; 15 and 30 feet below 
the top in the bluff south of Pennsylvania Highway 44, 150 yards east of the 
road to Oriole, east of Antes Gap, Williamsport (15’) Quadrangle; 5 to 6 feet 
and 50 to 60 feet below the top in the cut on Pennsylvania Highway 164, 100 
yards east of Plum Creek at East Sharpsburg, Hollidaysburg (15’) Quadrangle. 
Discussion.—The only species to which this one can be compared is L. brevi- 
limbata from which it differs in having finer wrinkles on the visceral region and 
a longer frill. 
BELLIMURINA Cooper, new genus 
(Latin bellus, pretty; murus, wall) 
Shell of moderate size, biconvex in young stages but concavo-convex in the 
adult. Hinge narrower or wider than the greatest shell width. Cardinal extremi- 
ties alate to obtuse. Surface marked by costellae of unequal size, the stronger 
ones separating groups of the smaller ones; in addition to costellae, visceral area 
of shell marked by zigzag wrinkles. Valves strongly geniculated toward the 
brachial valve just anterior to the biconvex visceral region. Pseudopunctate. 
Pedicle valve with moderately long palintrope, covered delthyrium; pseudo- 
deltidium large, convex; foramen small, apical. Teeth wide and large, dental 
plates flaring with small umbonal chambers. Delthyrial chamber moderately 
deep ; muscle field wide and short, with a low median adductor ridge. 
Brachial valve shallow but with a high and narrow peripheral rim; chilidium 
strongly convex, arching over a large cardinal process consisting of 2 parts, each 
with short shaft and myophore showing attachment surfaces for a pair of muscles 
located on the notothyrial platform. Brachial processes flat blades supported by 
callus deposited at a low angle to the hinge line. Median ridge short, adductor 
field small. 
Genotype.—Leptaena charlottae Winchell and Schuchert, Amer. Geol., vol. 9, 
p. 288, Apr. 1, 1892. 
Discussion—The members of this genus are not easy to recognize and may be 
confused with young of Limbimurina. The most significant feature of Bellimu- 
