442 Tra'M. Acad. Sci. of St. Louis. 



The third species of Chonetes in the fauna is represented 

 by a single specimen. It is smaller and proportionally nar- 

 rower than the last one, the length and breath being nearly 

 equal, 6.5 mm., and it is more strongly convex with rounded 

 radiating costae. The finer surface markings cannot be de- 

 termined. 



Camarotoechia sp. undet. 



Several incomplete specimens of a rhynohonelloid shell 

 having the aspect of members of the genus Camarotoechia, 

 occur in the Glen Park fauna. Except for a few very imma- 

 ture individuals, all the specimens observed are seperate 

 valves, all of which are more or less imperfect so that they 

 cannot be certainly identified. One of the larger specimens 

 has a length and width each of 10 mm. 



EUNELLA COMPRESS A n. Sp. 

 Plate l,flg»- 13-16. 



Description. Shell small, lenticular, compressed, the two 

 valves subequally convex, subovate to subcircular in outline, 

 longer than wide or sometimes wider than long, the greatest 

 width at or posterior to the mid-length of the shell. Pedicle 

 ralve with an acute, erect beak ; foramen circular or somewhat 

 oval; pseudodeltidium well developed; the surface flattened 

 along the median line from the beak to the anterior margin 

 and somewhat compressed on either side, giving to most spec- 

 imens the appearance of having two indistinct elevations, one 

 ©neither side of the flattened region, extending from the beak to 

 the front margin. Brachial valve usually slightly more convex 

 than the pedicle valve, most prominent posteriorly, flattened 

 along the median line to correspond with the flattened region 

 of the opposite valve; biachidium not clearly made out, but 

 its length is about one-half the length of the shell. Surface 

 of both valves smooth, shell structure finely punctate. 



The dimensions of one specimen are: length 6 mm., width 

 5 mm., thickness 2 mm.; of another broader specimen: 

 length 6 mm., width 6.5 mm., thickness 2.8 mm. 



Remarks. This is one of the common species of the fauna 

 and frequently occurs as complete specimens. In the erect 



