﻿25O SMITHSONIAN MISCELLANEOUS COLLECTIONS [VOL. 47 



genera are here absent. Another marked feature is that the 4 pri- 

 mary ambulacra are abundantly branched. 



SPHJEROCYSTITES MULTIFASCIATUS Hall 



(Plate XXXVIII, figures i, 2; Plate XXXIX, figures 1-4) 



Sphcsrocystites multifasciatus Hall, Nat. Hist. N. Y., Pal., in, 1859, p. 



130, pi. 7A, figs. 1-4. — Jaekel, Stammesgeschichte der Pelmatozoen, 



Berlin, 1, 1899, p. 289. — Schuchert. Amer. Geol., xxxn, 1903, p. 233. 



Sphcerocystis multifasciatus Haeckel, Die Amphorideen und Cystoideen, 



Beitr. Morph. u. Phyl. d. Echinodermen, Leipzig, 1896, p. 133. 



Length of one of the largest theca 19 mm. ; transverse diameter in 



both directions 24 mm. Another large theca has a length of 19 



mm.; diameter in the direction of the two upper pectinirhombs 20 



mm., and in the oppo- 

 <32 \ _2r~A site direction through 



x<f) f^L\ <c_r^ o^r tne anus 22 mm- ^ 



(^^^\fS \ K3^ f^vf^v'^ great.lv depressed speci- 



^^^^Vii 7 \\-L/fO men has a length of I3 



— \ N^ mm., and a diameter of 

 20 mm. A young theca 

 has a length and diam- 



Fig. 38.- — Analysis of Sphccrocystites multifasciatus & 



Hail. eter of 9 mm. Base of 



theca more or less ex- 

 cavated, greatest in the depressed specimens. Plate 12 rests on basal 

 plate 2. For general form, shape of individual plates and their 

 ornamentation, see the plate-figures and diagram. 



Ambulacra 4, branching rapidly and with no apparent regularity, 

 the branches varying between 14 in the youngest to 2y in the largest 



I ,,, ,,,. — Diagrams showing the manner and number of ambulacral branches in a 

 young, adult, and old specimen of S\ multifasciatus Hall. 



theca. These spread between and around the anus and pectini- 

 rhombs until the greater portion of thecal surface is occupied by 

 them, obscuring the suture lines between the thecal plates. Brach- 



