Plate 3. 



Page. 

 HIMEROCRINUS PLENISSIMUS (Lyon) 12 



Fig. 1. Photographic view, but little retouched, of an almost complete calyx, 

 showing the contour and surface sculpturing, from the deep basal 

 cavity (in which the basals are present, though invisible in the 

 shadow, without any columnals attached) to the high ridges at the 

 margin leading directly to the free arms. The generic diagram 

 (text fig. 5) was composed chiefly from this specimen, confirmed by 

 several others as to some details. An overlapping transverse fracture 

 interrupts the normal succession of plates in the upper part, but 

 their arrangement is clear in the right lower sector, where many of 

 the plates are slightly separated and the suture lines well marked. 

 Here may be seen a good example of the modified axillary primi- 

 brach, as well as one of normal size and form. On account of the 

 intricate sculpturing, no attempt has been made to outline the plates 

 in the upper part of this figure, although with proper lighting they 

 can be traced upon the specimen in the positions shown in the 

 diagram. The specimen is oriented with the posterior interradius 

 at the lower right, the small basal, here obscured by the shadow at 

 the bottom of the cavity, being plainly visible in the left anterior 

 position. The photograph is slightly under natural size, but owing 

 to foi-eshortening the picture appears still more reduced. Measuring 

 from l)ase to margin, and allowing for the overlapping fracture, the 

 spread of calyx is at least 15 cm. (Pee also text fig. 5.) 



2. Photograph of dorsal side of a specimen minus base, showing a style of 



ornament formed chiefly by pits instead of grooves. Here the axil- 

 lary primibrach is of full size throughout. The second inter- 

 brachial range has an extra plate in two interrays, so the anal side 

 can not certainly be identified. 



3. Dorsal (exterior) view of detached l)atfals of a similar specimen, with 



part of column adhering in the cavity, and radials attached. 



4. Ventral (interior) view of detached base, with some radials attached, 



showing division of the basals, their deep inward projection, and the 

 large pentapetalous axial opening. 



Onondaga: Louisville, Kentucky. 



62 



