INVERTEBRATES. 515 



Genus DIOHOOEI^US, Munster. 

 DiCHOCREsrus picus, C. and L. 



PI. 29, Fig. 7. 

 JDichocrinm Jicus, Cassedat and Lyon, 1860. Proceed. Am. Acad. Arts and Sei., Vol. 5, p. 24. 



Body subovoid, inflated near the middle of the first radials, from 

 ■which it gradually contracts both above and below. Basal pieces simi- 

 lar in form and size, and when uuited presenting five slightly curved 

 depressions and one angular notch for the reception of the radial and 

 anal pieces. First radials five, similar in form and size, longer than 

 wide, sub-quadrangular; the upper margin slightly indented for the 

 reception of the second radials; second radials, six very small, semi- 

 circular; third radials, six small, cuneiform, axillary, supporting on 

 their npper sloping sides two arms. Anal piece similar in form but 

 narrower than the first radials, and like them it supports a second and 

 third radial and a pair of arms. Arms twelve, composed at their bases 

 of rather stout pieces nearly as long as wide, but growing shorter above, 

 and giving off numerous pinnulw to their extremities. 



Position and locality: Crawfordsville, Indiana; from the shaly beds 

 of the Keokuk Group, Lower Carboniferous. 



Genus BAEYCEINUS, Waclisimitli. 



Baeycbinus steiattjs, Worthen. 



PI. 20, Fig. 5. 



Body rather large, broadly obconic and composed of massive plates. 

 Basal series very small and almost entirely concealed in the columnar 

 depression. Subradials large, pentagonal i nearly triangular in outline, 

 the upper angle being a little longer than the laterals. First radials 

 nearly quadrangular, a little wider at the top than the length to the 

 middle of the facet for the reception of the next range of radials. 

 This facet is moderately concave, and sloping outward occupies about 

 one-half the width of the first radial pieces. Anal piece large, a little 

 longer than its greatest width, and rather more than half as large as 

 the first radials. Surface ornamented with four or five prominent stria? 

 that begin at the base and run parallel with the lateral borders of the 

 subradials to their upper angles, and thence diverge to the centre of 

 the facet on the upper margin of the first radials. A granulose structure 

 is also observable on the remaining portion of the body plates. These 



