INDIANA PALAEONTOLOGY. 93. 



The upper ends of the radials project upward distinctly. 



The anal spiracle is of moderate size and round. 



There are eight other spiracles which would seem to indicate that our 

 species is not Pentremitidea, but otherwise the resemblance is close, and there 

 isn't sufficient excuse for referring it to any other genus or erecting a new 

 genus for its reception. The minute interradials hardly distinguishable in the 

 specimens, save the anal piece, are unmistakable Pentremitidean characters. 

 It is widely separated from any subcarboniferous genus as Schizohlastus, to 

 which there is a superficial resemblance. 



Horizon, locality and collection same as the last. 



PENTREMITIDEA y APPROXIMATA, N. Sp. (Rowley). 



Plate 30. Fig. 8. 



The specimen here figured is somewhat injured about the base, but is suffi- 

 •ciently well preserved to show that the basal plates form a less pronounced 

 ■convexity. 



The body in side view is elongate elliptical and the radials are almost as 

 iong as the entire body. The interradials except the anal plate, are not visible 

 •on a side view, and are probably confined to the summit. 



The ambulacra are somewhat wider in proportion than in the last de- 

 scribed species, and extend above the grooves that hold them, thus differing 

 widely from P. dub) a. 



The upper ends of the radials are depressed and a cross section of the 

 body is decidedly pentangular. (Compare with figure 6 of P. duhia). Our 

 specimen is not unlike Pentremitidea leda, but has double spiracles instead of 

 single in that species. The anal opening is round and there are eight spiracles. 



The horizon, locality and collection same as the last. 



PENTREMITIDEA LEDAVVar. magna, N. Var. (Rowley). 

 Plate 30. Figs. 9-10. 32-33? 



There is some doubt about the reference of this specimen to Hall's species. 



The three basal plates form a low convexity and the columnar facet is 

 «mall. 



The radial plates are little less than the entire body length. The interra- 

 dials are small, but apparently visible on a side view. The ambulacra are of 

 moderate width and quite as long as the radial plates, and forming with the 

 upturned lips of the grooves, low, rounded ridges. The ambulacra are not at 

 xiU sunken. 



