148 University Geological Survey of Kansas. 



the ventral margin nearly obsolete ; sinus along the hinge line 

 widening considerably at the posterior extremity, making the 

 posterior umbonal convexity narrow. Valves rather convex. 

 There are three long teeth on the posterior portion of the hinge, 

 nearly parallel, but apparently do not reach more than one- third 

 the distance from the posterior to the anterior end of the shell ; 

 beneath the umbo there are four or more small, comb-like, trans- 

 verse teeth. In front of these there is a thickening of the shell ; 

 anterior to the thickening of the shell, and near the front, are 

 one or two large, oblique teeth making an angle of about 45° 

 with the hinge line. Concentric lines of growth visible, dis- 

 tinct but not prominent. Length, 20 mm. ; height, 7 mm. ; 

 convexity, single valve, 5 mm. 



Range and distribution : Upper Coal Measures ; Olathe, Tur- 

 ner, Lawrence. 



I am able to find no trace of radiating striae, mentioned by 

 Meek, on these specimens. However, the specimens appear to 

 have been water- worn before being enclosed in the matrix, and 

 may have been abraded. The specimens seem to be identical 

 with some from Carbon Hill, Ohio, except that the latter are a 

 little larger. The hinge markings are also very similar. The 

 anterior margin of the shell often meets the hinge line at an 

 angle of less than 90° ; otherwise it seems to correspond very 

 well to 31. obsoletus. 



NUCULANA. 



Likn, Rost. Samml., Ill, p. 55, (1807). 



Nuculana bellistriata. Plate XX, figs. 14, 14b. 



Leda bellistriata Stevens, Amer. Jour. ScL, (2), xxv, p. 261, (1858). 

 Nucula, {Leda) kazanensis Swallow, Trans. St. L. Acad. ScL, i, p. 190,. 



(1858). 

 Nuculana bellistriata White, 13th Rep. Ind. St. Geol., p. 146, pi. xxxi,. 



ff. 8, 9, (1884). 



White's description : " Shell transversely elongate-subovate, 

 gibbous anteriorly and attenuate behind ; basal margin broadly 

 convex, straightened in the middle ; anterior margin narrowly 

 rounded ; posterior margin very narrow ; postero-dorsal mar- 

 gin nearly straight, sloping backward and a little downward 

 from the beaks ; umbonal ridges well defined, situated near to- 



