338 THE CRINOIDEA CAMERATA OF NORTH AMERICA. 



as the radials ; they are Vv^idest next to the intercostal sutures^ tapering to 

 both ends ; the lower lateral faces convex, and longer than any of the 

 others; the upper faces meeting the interbrachials of the second order. The 

 two latter plates combined are but little smaller than the lower one, their 

 tips rising conspicuously above the arm facets, and very little truncated. 

 Interdistichals much smaller than the corresponding interbrachials, their 

 lower ends touching the costals or resting between the upper slojoing 

 faces of the distichals. The remaining parts of the species are not shown 

 in the specimens, but it may be suggested from the condition of the inter- 

 brachials and interdistichals that the partition walls were unusually thin. 



Horizon and Locality, — Niagara group ; AValdron and Hartsville, Ind., 

 Lockport, N. Y., and Racine, Wis. 



Types in the Museum of Comparative Zoology. 



RemarJcs. — Miller and Dyer, in their specific description, after giving 

 the structure of the brachials, and stating that the first interbrachials are 

 '' nine or ten-sided," continue as follows : '^ This description applies to the 

 two ten-sided interradials ; the other three have only nine sides, as shown 

 by Plate 2, Fig. 9, and differ in supporting one supraradial instead of two." 

 Even if this were true, which is not the case, it would have no specific sig- 

 nificance, but would only indicate an abnormal condition of that specimen. 

 By giving the specimen some additional cleaning, we disclosed two distichals 

 in every ray, all supporting two extremely small palmars, as shown by our 

 figure (Plate LXXXIII, Fig. 9). The peculiarity that some of the inter- 

 brachials are nine-sided, is caused by the distichals, which in three of the 

 rays lean over to one side, so that one of them does not touch the interbrach- 

 ials. In Miller and Dyer's second type. Fig. 9a on the same plate, wdiich 

 we also reproduce (Plate LXXXIII., Fig. 8), the respective plates are all 

 ten-sided. 



We must regard Eucalyptocrinus muralis Ringueberg as specifically iden- 

 tical with E. tubercidatus, until better specimens are found. Of Ringueberg's 

 type, which we had for comparison, only the dorsal cup is preserved, and this 

 is so badly crushed as to give no idea of its actual form. It is quite possible 

 that the base is somewhat broader than in Miller and Dyer's types, that the 

 plates generally are a little more convex, and the tubercles upon the plates 

 somewhat less prominent, but the proportions of the plates are substantially 

 the same. Similar variations may be expected in the limits of any species. 



