HAMBACH NEW PALAEOZOIC ECHINODERMATA. 553 



Pentremites gemmiformis, n. s. 



(PL D, Fig. o.) 



Body gemmiform. Pelvis cylindrical, except the upper mar- 

 gin, which is bent a little outwards ; its length amounts to fully 

 one-third of the entire length of the calyx, whereas its transverse 

 diameter is a little less than half of the greatest transverse diame- 

 ter. Fork-pieces nearly twice as long as wide ; its base portion 

 occupies not quite one-half of the piece, sloping from the centre 

 gently sidewards and downwards, so that the lower part of the 

 body is rather a little longer than the upper one ; sinus for the 

 reception of the ambulacral field broad. Deltoid pieces &mall, 

 arrow-head shape, twice as long as w^ide, and do not reach up to 

 the summit. Ambulacral field broad, slightly convex, and sunk 

 a little into the sinus, so that they are surrounded by a fine ele- 

 vated crest of the fork-piece, which becomes more prominent 

 near the base of the field, but less towards the apex. Lancet 

 pieces half as wide as the field. Poral pieces comparative!}^ large, 

 counting eight to one-tenth of an inch. All apertures on the 

 summit rather large, but closely arranged. Surface apparently 

 ornamented with very fine striag running parallel to the sutures. 

 Interambulacral space flat and not depressed. 



Geological fonnaiion and locality — In the Kaskaskia limestone, 

 Randolph county, Illinois. Rare. The specimen is in the col- 

 lection of the Washington University. 



This species resembles somewhat Pentremites calycinus Ly- 

 ons, but is easily distinguished by its more robust base portion, 

 by having no constriction around the same near the articulation 

 surface of the column, by the larger poral pieces, and the less 

 transverse diameter. 



To show better the difference between Pentremites gemmifor- 

 mis and calycinus^ I have also given on PI. D two figures of the 

 last named one in Figs. 6 and 7. 



Genus CoDONiTKS Meek and Worthen. 

 Codonites campanulatus, n. s. 



(PL D, Figs. 8,9.) 



Body bell-shaped. Base portion composed of three pieces as 

 in the true Pentremites^ cup-shaped, its upper diameter about 

 three times as large as the articulation surface of the column with 

 a slight constriction in the middle, thus giving to the lower part a 



