32 



lipjlit. The first ami third {)]ates thus described support three 

 pldtes iu the next i-ange, whicli are succeeded l>y plates of the 

 proboscis. 



The proboscis is large, long, eyliudrical, aud covered with polyg- 

 onal plates. Round pores penetrate the proboscis throughout its 

 length at nearly every angle of the plates, and, frequently, on the 

 sutures between tin' angles. The vault is covered with small 

 plates. 



This species is more nearly related to P. siihrdinosus than to 

 any other which has been described, but it is distinguished from 

 that species by the; relative proportion of the plates in the calyx' 

 by the number and position of the azygous plates, and by the 

 great difference in the arms, aud no doubt, also, in the character 

 of the proboscis, which is unknown iu that species. 



Found iu the Keokuk Group, at Cravvfordsville, Indiana, and 

 now in the collection of Wm. F. E. Gurley. 



ZEACRINUS GRANDICULUS, U. Sp. 



Plate If. Fig. 31 . azygous rieic; Fig. 32, vieir opposite the 

 azijgoTo.'i area. 



Body rather large, robust and elongate-ovate in outline. Calyx 

 very low. Columnar cavity shallow. Surface smooth or finely 

 granular. Column very small, round and composed of thin plates. 



Basal plates within the calyx. Subradials with an acute superior 

 angle, but invisible in a lateral view. First radials about one- half 

 wider than long, rapidly expanding to the superior lateral angles, 

 and truncated the entire width above for the support of the sec- 

 ond primary radials. The iuferior angles do not extend into the 

 columnar cavity. Four of them are pentagonal, but two of them 

 are separated by th3 extension of an azygous plate so as to reach 

 the point of a subradial, and the one on the right supports two 

 azygous interradials, as well as the radial series which gives to it 

 an heptagonul outline. Four of the second primary radials are 

 pentagonal, one-half wider than high, axillary, and support on 

 each upper sloping side the secondary radials; but in the ray 

 opposite the azygous area there are three primary radials, and 

 consequently the second is quadrangular, twice as wide as high, 



