32 BULLETIN 64, UNITED STATES NATIONAL MUSEUM. 



MARSIPOCRINUS VERNEUILI (Troost). 



Plate 9, figs. 10, 11, 12. 



Cupellaecrinites verneuilii Troost, Proc. Amer. Ass. Adv. Sci., II (read 1849), 1850, 

 p. 61; Mss., 1850. 



The original ^description is as follows : 



This little Cupellaecrinites [Marsipocrinus] approaches in its general form the C. 

 laevis [C. tennesseeae]. 



Pelvis [base] — pentagonal. — The impression for the column pentagonal [circular], 

 very large and surrounded with an elevated margin; the angles of this elevated border 

 not opposed to the angles of the pelvis [base] but intermediate; alimentary [axial] 

 canal pentagonal. The whole of the lower surface corrugate. The division of the 

 scapulars [secundibrachs] very plain. 



This species is ornamented by series of tubercles [ridges] numerous, irregular; 1st 

 upon the hexagonal costal [radial] rests a small cuneiform plate which supports two 

 larger plates which cover at the same time one-half of the superior margin of the costal 

 [radial], upon this plate (the one that is supported by the above-mentioned cuneiform 

 plate), rests another cuneiform plate which projects considerably beyond the general 

 circumference of the body and supports partly the plate in which the horse shoe exca- 

 vation for the hand [arm] is situated. — This is repeated on the other inclined plain of 

 the said cuneiform plate. As all these plates are tumous and corrugate the joints are 

 easily observed — in fact, though small, it exhibits its characters better than any other 

 species; but it is particularly its plated coronal integument which is admirable and 

 which seems to have been formed from a complicated design copied from those exhib- 

 ited by the kaleidoscope. It is a kind of mosaic composed of three stars, the one sur- 

 rounding the others. — The smallest, or central one, is composed simply of five rhombs 

 [orals] — between the reentering angles of which, are placed five subpentagonal plates 

 [interambulacrals] so as to project far beyond the rhombs of the first star — this forms 

 the second star which projects for about half the radius of the whole circular integu- 

 ment except on one of its angles where we have the oral [anal] aperture (only discov- 

 ered on this and on the C. magnificus). This star is followed by the third which is 

 more complicated. We have first five pair of double points [interambulacrals], — two 

 elongated polygonal plates joined side by side — they are separated on each side by 

 two rows of small tubercles [ambulacral plates] which proceed from the central star 

 to — and penetrate the aperture of the hands [arms] after being divided as seen in the 

 figure; secondly we have five single points [plates] projecting a little beyond the double 

 points [of the interambulacrals], from which they are separated by two rows of double 

 series of tubercles [ambulacral plates] as mentioned above. 



Observations. — The elevated rim around the column is a well- 

 marked feature of the species. It has an irregular outline, suggesting 

 a pentagonal or triangular form. The surface is beautifully orna- 

 mented with delicate, irregularly branching ridges which on the 

 radials appear to start at the center of the upper margin, radiating 

 outward and downward, and on other plates to pass transversely 

 across them. 



Troost' s description and figures of the tegmen represent it as 

 nearly radially symmetrical, taking too little account of the irregu- 

 larity produced by the anal area. The five oral plates are tumid and 

 easily distinguished. They are grouped on the anterior half of the 

 tegmen, as shown by fig. 12, plate 9. The anal aperture is sur- 

 rounded by several rows of minute plates which merge into those of 



