﻿SCHUCHERT] siluric \m» devonk cystidea 2 S l 



ioles wid :ly separated, about 3 in 5 mm.; club-shaped, tapering to a 

 point, and about 3 nun. long. Ambulacrals large, to each oi winch 

 there are aboul 5 ambulacralia. 



Dichopores in sharply delimited, low, angulated, discrete pits; in 

 odier words, the grooves of the 2 pans of the pectinirhombs do not 

 meet each other at the suture lines of the plates of which they are 

 a part, but are restricted to the prominent pits. From 40 to 45 

 grooves in each pit. 



Anal pyramid depressed, composed of 6 pieces and surrounded by 

 a ring of 3 large ahoral and 7 small oral pieces. 



Hydropore minute, closed by a pyramid of 4 pieces, and situated 

 immediately in front of the large madreporite occupying the greater 

 portion of plate 18. 



Column slender, with about 16 stout and equally large segments 

 beneath the theca, followed by others of unequal size of which the 

 larger segments are widely separated. 



Formation and locality. — Hall states that his specimen came from 

 " the limestones of the Lower Helderberg group, Cumberland, Mary- 

 land." This usage of " Lower Helderberg " is the old one. now 

 obsolete, including the Tentaculite limestone or Manlius formation. 

 About Cumberland, this species is very rare, probably not more 

 than four specimens are known, but in the quarries near Keyser, West 

 Virginia, more than 4,000 specimens have been picked up during the 

 last three years. Here they range through the middle layers for 

 about 37 feet, associated with the other common cystids, S. globularis, 

 Pseudocrinites gordoni, Jaekelocystis hartleyi, and several species 

 of crinoids. 



Cat. numbers 35,052. 35,058, U. S. X. M. 



SPHJEROCYSTITES BLOOMFIELDENSIS n. sp. 



Length of theca 14 mm. ; diameter 15 to 16 mm. Depressed glob- 

 nlar, with the base not excavated. 



Thecal plates arranged as in S. globularis; otherwise this species 

 is closely related to S. multifasciatus. 



Of this form, the two known theca- were greatly exfoliated in break- 

 ing them from the shaly limestone, so that most of the specific charac- 

 ters are not determinable. However, the shape allies the species with 

 S. multifasciatus from which it differs in having no excavated base 

 and in plate 12 not resting on plate 2 of the basal row, but upon plate 

 6 of the second row as in S. globularis. It probably differs further, 

 not only in the smaller and more spheroidal theca, hut also in having 

 the ambulacra less branched. From 5". globularis it is distinguished 



