119. 



CONTRIBUTION TO 



The P. cervinus group seems to eoiniect the P. 8ul<*atu8 and /-•, godoni 

 series and emhraces P. cervhius and P. nodoscK. 



Penti'ernltes ((ltd 8 seenjs to belong to the Pyrit'onnls group, while P. genn- 

 in'it'ointila is perhaps a sj-nonyni of P. calijci nns. 



P. ahhreolatuH is hardly tlistinct from /-*. godod. 



Of P. glohoaus, P. //n',s8r>i//'n'/i8<8 and 7-*. t roost i little seems to be known, 

 while other species as /\ tr>inr((tns, P. stthconoideus, P. longicostalis and/-*. 

 dec If, status probably dt) not belong to the genus. 



/^ latci'iiit'oi'tiiis is the internal east of some large species of Pentremites. 



P EN TKEMIIVES Sp.? 



Plate 36. Fio. 13. 



We are unable to refer this form to any species with which we are ae- 

 ijuainted. It evidently lielongs to the P. piirtfoi'iiiis type, and, although it bears 

 a sui)erficial resenil)lance to /-*. aiigulai'iH. it cannot be placed there as that 

 is within the realm.of the sulcatus group. We hardly care to found a species 

 on the evidence of one fossil but should future research prove the constancy of 

 these characters in other specimens, we would suggest the name Pentremites 

 sperio-'oix. 



The l)ody is doubly conical, the part below the distal ends of the ambulacra 

 being much deeper than the part above. 



The large basal plates form a strong conical cup and are quite one third of 

 the body in height. The radial pieces are but little more tlian half the entire 

 body lu'ight. The deltoids are (juite <uie third the ambulacral length but do 

 not (juite reach the summit. The ambulacra are of moderate width, almost flat, 

 lying but little below the l)ounding radial and interradial e'dges and less than 

 half the l)ody in length. 



The inter-anil)ulacral si)aces are flat and the outline boundary from the am- 

 bulacral ti[) to the stem base is an obliipie line, almost straight. The ventral 

 or toi) surface is cjuite broad, s]:)iracles round and but little smaller than the 

 anal opening and the uncoveretl central space is a small, symmetrical, five 

 pointed star. 



The number of pi re pieces on one side of an ambulacrum is about thirty- 

 five, or seventy to the whole area. 



The column was quite strong. 



On account of the poorly preserved character of the surface nothing can be 

 determined as to the external ornamentation. 



From the Kaskaskia group of (Jrittenden county, Kentucky, and the collec- 

 tion of G. K. Greene. 



