MILWAUKEE CRINOIDS. 119 



specimens used by Hall in his description are recorded as com- 

 ing from the drift about Milwaukee and also from Iowa City, 

 Iowa. It is possible that Hall included in his species all the 

 nodose forms from Milwaukee, but from a study of a consider- 

 able number of specimens I am led to recognize two good spe- 

 cies. Whitfield's illustration of the species is drawn from the 

 largest of Hall's type specimens, and, except in its larger size, 

 differs in no essential respects from the one here illustrated. 



Although two species and one named variety, of these no- 

 dose forms are recognized in the present paper, it is possible 

 that some would prefer to include them all in a single variable 

 species. All the specimens, however, which have come under 

 my observation can be placed without hesitation in one of the 

 two recognized species, M. nodosiis and M. subglobosiis, but it is 

 more difficult to separate the variety spinosiis from the t}^pical 

 specimens of M. nodosiis. The distinguishing differences be- 

 tween the two species will be pointed out in connection with the 

 description of M. stibglobosus. 



With the exception of the associated M. siibglobosus^ Mdo- 

 crimts nodosiis is quite distinct from any other species of the 

 genus. It need only be compared with M. calvini ^ from the 

 Devonian ot Johnson Co., la., and M. gregerr- from the Devo- 

 nian of Callaway Co., Mo., and from both of these species it 

 differs in its much more strongly nodose plates. 



Melocrinus nodosus var. spinosus n. var. 

 (PI. XIV. Fig. 2.) 



This variety differs from the typical form of the species in its 

 higher and narrower calyx, and in its more pointed spine -like 

 nodes. 



iWachsmuth and Springer, N. Am. Crim. Cam., Vol. I, p. 300, PI. XXII, 

 fig. 6. 



2 Rowley, Am. GeoL, Vol. XII, Nov. 1893, p. 303, PI. XVI, fig. i. 



