204 TRANS. OF THE ACAD. OF SCIENCE. 
Bet.eroPpHon Merxianus, Swallow. 
Shell small, gibbous, broadly rounded on the dorsal vm 
carinated near the aperture, ornamented with it crow tie 
points of cuition on to ‘ie adjace ent whorl ; Ber con- 
tered is umbilicus shallow, distinctly modified by the thick 
reflex 
"Diameter 0.77; width of aperture, 0.60; length of aper- 
This beautiful little oor Meco the B. perlatus of Con- 
rad, (Jour. Acad. N. 8. Phil., Vol. VIIL, p. ap) but his speci- 
men has no transverse tha and ours is carinated only near 
the aperture. It is also similar to B. Witryanus, D’Koninek 
(An. Fos., pl. 28, fic, 9, p. 341); but the latter is easily dis- 
tinguished by its very ‘large umbilicus. B. decussatus, Flem- 
(Phil. Ge. York eevol I). p. 281, pl. 17, fig. 18,) may be 
oma by the greater depth of the umbilicus and its well 
carina. 
Missouri State collection from the Middle Coal Measures 
; also by Mr. Price in the Lower Coal pa 
\PHON TRICARINATUS, Shumands. 
: ‘no surface mar preachy” 
Zoe. Upon Coal Measures, eK. oT. ee 
