BATOCRINIDiE. 377 



The smallest known species of Batoo-inus. Height of crown not exceed- 

 ing 3 cm. Calyx about as wide as high, the arm bases projecting. Dorsal 

 cup obconical; sides straight from the bottom to the top of the distichals, 

 thence curving more abruptly outward ; base broadly truncate. Plates 

 slightly convex, without ornamentation; suture lines depressed. Color of 

 specimens lighter than that of Rliochcrinus Ki?-iyi and Dichocrimis inornatus 

 from the same locality. 



Basals short, forming a broad hexagonal disk, which is but very little 

 excavated at the bottom. Radials considerably wider than long ; their upper 

 faces concave. Costals small, quadrangular and pentangular ; the first con- 

 vex below, more than twice as wide as long ; the second not longer than the 

 first but wider. Distichals 2 X 10 ; followed by two rows of cuneate palmars, 

 which support the free arms. Arms twenty, comparatively heavy, rounded 

 on the back, the tips slightly incurved and somewhat flattened. Inter- 

 brachials three, sometimes with a small one on top ; the first extending 

 to the full length of the first distichals, those of the second range arched 

 over by the palmars, except at the posterior side where a narrow piece 

 intervenes between them. The anal plate is followed by three rather 

 large pieces, and these by two and one. The ventral disk is a little lower 

 than the dorsal cup, highly convex, and slightly depressed at the interradial 

 and interdistichal spaces; the ambulacra elevated, and covered by several 

 nodose plates of a first and second order. The interambulacral spaces are 

 paved by numerous very small, convex pieces. Orals comparatively small. 

 Anal tube slender, shorter than tisnal in this genus, extending but little 

 above the tips of the arms. Column short, the nodal joints in the upper 

 part large, rounded at their edges ; the intervening joints comparatively 

 short and narrow, contrasting strongly with the nodal ones. Toward the 

 lower end the joints are more uniform. The column has been observed by 

 us to its full length in several specimens, in none of which it measures 

 more than six inches. It generally tapers to its distal end, where it termi- 

 nates in a sharp point. The lower part, to about one third of its whole 

 length, bears short lateral cirri, which are arranged singly — not in whorls. 



Horison and Locality. — Kinderhook group; Le Grand, Marshall Co., 

 Iowa. 



Types in the collection of Wachsmuth and Springer. 



