8 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. ']6 



sulci. Arms slender, numerous (facets for 56 in the specimen before me), 

 arising directly from the upper straight edges of the secondary radials. 

 Column large, round, the superior joint concealing the basals and nearly the 

 whole of the primary radials. 



A fuller description is given under the type species, as follows, 

 p. 358, foot-note : 



Catillocrinus fennesseeae. Cup hemispherical, width one and a half times 

 greater than the height. Base (concealed by the column) small, pentagonal, 

 situated in a deep cavity, and projecting into the interior in the form of a 

 low cone. Primary radials forming united an irregular pentagon, with curved 

 margins which scarcely rise above the plane of the under surface of the cup, 

 almost entirely concealed by the last joint of the column. Secondary radials 

 very irregular in form, thick, convex; two very large, transverse, forming 

 almost two-thirds of the cup; expanding rapidly from below upward so as to 

 embrace nearly the whole of the superior circumference ; between these on one 

 side are wedged in two of the smaller pieces, one of them quadrangular with 

 nearly parallel sides, the other linguaeform, and opposite these is a large 

 quadrangular piece with sides converging from below upwards. 



Adapted to present terminology, the foregoing descriptions un- 

 doubtedly call for a dicyclic base. Three ranges of calyx plates are 

 described, one of them being the irregular radials w^hich cannot be 

 mistaken for anything else, and two others below these. Lt is clear 

 that what the author called " primary radials " are our basals, and 

 what he called "basal pieces" are our infrabasals; the latter form 

 a " low cone, projecting into the interior," and the former an " irregu- 

 lar pentagon with margins which scarcely rise above the plane of 

 the under surface of the cup " ; and both of them are covered by the 

 last joint of the column, which conceals " the basals and nearly the 

 whole of the primary radials." In the generic diagnosis the number 

 of small " basal pieces," forming the " low cone," is stated as " 5," 

 while in the specific description the number is not given. Shumard 

 evidently had a very definite idea of the structure before him, and 

 there is no ambiguity in his description. Wachsmuth and Springer, 

 upon the evidence of other specimens accessible to them, but without 

 having seen Shumard's, disputed his interpretation of the structure 

 and maintained that there are " only two series of plates." 



The descriptions in Troost's previously unpublished monograph 

 were copied by Miss Wood in Bulletin 64, pp. 23, 24, where they may 

 be consulted in full. They are not material to the present inquiry, 

 except for the statement in the generic diagnosis:." Pelvis (base) 

 subpentagonal, divided into 3 unequal plates " ; and in the specific 

 description : " Pelvis (base) irregular pentagon, more or less con- 

 cave, bearing a circular impression for the column which occupies 



