3<D2 SMITHSONIAN INSTITUTION 



Synaptocrinus nuntius (Hall) 

 Plate XXXVIII, figs. 3-6 



Forbesiocrinus nuntius Hall, 15th Report New York State Mus. Nat. Hist., 1862, p. 124 (Separate, p. 96) ; 



Bull. I, New York St. Mus., Photographic Plates, 1872, pi. I, fig. 12. 

 Taxocrinus nuntius, Meek and Worthen, Proc. Acad. Nat. Sci. Philadelphia, IX, 1865, p. 140.— Wachsmuth 



and Springer, Revision Palaeocrinoidea, I, 1879, p. 49. 

 Rhodocrinus {Taxocrinus) nuntius, Shumard, Trans. Acad. Sci. St. Louis, II, 1866, p. 398. 



Type of the genus. 



Specimens usually small, but may attain large size. Crown elongate, widest 

 about the third bifurcation, where height to width is 1 to 1.3; spread of calyx 

 from perimeter of column facet to IAx, i to 2.5 ; cross-section at that level stel- 

 late; side outline straight; base concave, the concavity filled by column and 

 including the basals except for small points sometimes exposed. Rays strongly 

 elevated and angular in the middle ; primary plates and axillaries nodose ; sutures 

 sinuous. Surface strongly ornamented with small papillae, tending to coalesce 

 into longitudinal wrinkles. A large crown is 20 mm. high to about fourth bifur- 

 cation, probably extending considerably higher; width, 24 mm.; base outside of 

 column, 7 mm. 



IBB small, filling about half the diameter of column facet. BB small, 

 visible only in small angles beyond the column, except the post. B, which is greatly 

 elongated, extending to the full height of RR, and terminating in an acute angle, 

 leaving no surface for attachment of anal plates. RR wider above than below, 

 elevated into large, angular, median nodes resembling short spines projecting 

 downward over the proximal columnals, with lateral margins flattened toward 

 the sutures; similar nodes surmount the two primibrachs and all axillaries be- 

 yond, the intervening brachials being elevated and sharply angular in the middle. 

 All brachial plates are much wider than long, and have the lateral margins 

 abruptly deflected from the median elevated part into low, wing-like buttresses, 

 which meet at the interradial sutures and interlock; just at the edge they often 

 have a slight elevation or fold parallel to the median line, strongly resembling 

 rows of interbrachial plates. IBr increasing rapidly in width upward in line 

 with margins of RR. IIBr 3 ; IIIBr about 4 to 6 or 7, the longer intervals being 

 in the outer ramii, some branches bifurcating once more. Column large next to 

 the calyx, where it fills the concave base; it diminishes gradually for about a 

 dozen moderately thick, rounded and equal ossicles, with thin projecting rims; 

 below that they become thicker and more rounded, with large ones at intervals 

 of four or five. 



The description of brachial structures is chiefly taken from the large specimen obtained 

 at a different locality from the type (PI. XXXVIII, figs. 40, b) ; the nodes are less accentuated 

 in smaller specimens, but the angularities and general features of surface marking are the 

 same. Out of four well marked specimens, three are about equally small ; but notwithstanding 



