MOLLUSCA. 427 



Inoceramus confertim-annulatus Rcemer. 

 Plate XXXIX., Figs. 2-5. 



1849. Inoceramus confertim-annulatus Roem., Texas, p. 402. 

 1852. Inoceramus confertim-anmilatus Roem., Kreid. von 



Texas, p. 59, tab. 7, fig. i. 

 1857. Inoceramus confertim-annulatus Con., Rep. U. S. and 



Mex. Bound. Surv. vol. i, pt. 2, p. 151, pi. 5, fig-. 5. 

 1886. Inoceramus Barabini Whitf., Pal. N. J., vol. i (Monog. 



U. S. G. S., vol. 9), p. 75, pi. 15, figs. 3-5. (Not /. 



barabini Morton.) 



Description*. "Shell of only moderate size, transversely ovate 

 or elliptical, with moderately to prominently convex valves. 

 Beaks large, only slightly projecting beyond the line of the hinge, 

 and situated near the anterior end. Hinge-line two-thirds as 

 long as the shell, and rapidly rounding at the posterior extremity 

 into the posterior margin, which is more broadly rounded than 

 the anterior extremity. Basal line gently and somewhat gradu- 

 ally arcuate, but more rapidly curving upward near the anterior 

 part. Surface of the shell marked by regular concentric, rounded 

 undulations parallel to the margin of the valve, and separated by 

 concave interspaces. Near the outer limits of the valve the 

 undulations become more irregular, as if taking on old-age char- 

 acters." (Whitfield.) 



The dimensions of the two specimens illustrated by Whitfield 

 are : length, 54 mm. and 50 mm. ; height from hinge-line to 

 ventral margin, 39 mm. and 36 mm. ; convexity of the larger 

 specimen, 14.5 mm. 



Remarks. These shells were identified as /. bambini by Whit- 

 field, but they seem to differ essentially from that species as 

 interpreted by Meek, and his interpretation, based upon a careful 

 study of Morton's imperfect type specimens, seems to be entirely 

 correct. The most conspicuous feature of the true /. barabini is 

 the much greater height of the shell posteriorly than in front, 

 while in the New Jersey specimens the height of the shell beneath 

 the beak is nearly or quite equal to that near the posterior ex- 

 tremity of the hinge-line. The New Jersey shells much more 



