976 



MR. F. A. BATHEB ON TJHSTTACRINrS. 



[Dec. 17, 



the Niobrara Chalk of Trigo Co., W. Kansas, associated with the 

 Odontornithes, Pterodactyls, and Mosasauroid reptiles of that 

 formation. One of these crinoids, which was sent to the Tale 

 College Museum, sened Grinnell as the tj-pe of genus and species, 

 Uintacrimts socialis, which he described in 1876 (2). The speci- 

 mens studied by him showed neither base nor arms clearly (fig. 1, 

 p. 975). Some specimens sent at the same time from Prof. Mudge 

 to r. B. Meek were well described by the latter (3), who added a few 

 details concerning the interradial and interdistichal areas (fig. 2). 

 Still there remained to be determined " the nature of the base 

 (whether composed of five pieces surrounding a central piece, and 

 whether or not it was connected with a column), the presence or 

 absence of subradial pieces, and whether there is an anal series of 

 pieces differing from each of [the other] interradial series." 



Fig. 2. 



Uintacrimts socialis. Eeproduction of Meek's fig. B, in Bull. U.S. Geol. & Geog. 

 Survey, ii. p. 375. " A flattened specimen, [in which] all the body-plates 

 of one side are seen. The plates of one interradial area (middle oi' figure) 

 [interbrachials, mihi] and parts of two others, one on each side, as well as 

 those of two of the interaxillary areas [interdistichal.s, mihi], are shaded 

 to distinguish them from the plates of the radial system [fi.\ed brachials, 

 mihi], which latter are marked with dotted lines." Natural size. This 

 specimen is in the U.S. National Museum, and has been re-figured by 

 W. B. Clark (8). See page 982 and PI. LVI. fig. 1 a. 



Almost contemporaneously a specimen of this genus, but repre- 

 sentative of another species, was discovered in Europe at a slightly 

 higher horizon, namely in the lowest division of the Lower 

 Senonian, in the Marsupites zone, near Recklinghausen in 

 Westphalia. This was exhaustively described and discussed by 

 Schlueter in 1878 (4), under the name U. westfalicus (fig. 3). In 

 this specimen the arms were not well preserved ; the base, which 

 was clearly seen, confirmed the impression of previous writers 

 that the genus was unstalked, and showed that there was but one 



