18 



DOLATOCRINUS A.PLATUS, n. sp. 



Plate 111. Fit/, la, basal view; Fig. 17, summit view; Fig. t8, 



side view. The suture lines ore too indistinct on the 



vault of our specimens for illustration. 



Species medium size, very short or much depressed, vault 

 and calyx subequal in capacity Calyx low, more than three 

 times as wide as high, rounding out from a deep basal cavity 

 and spreading, without any constriction, to the tree arms. 

 Surface deeply sculptured. Radial ridges very small hut made 

 SOmewhal conspicuous by the elongated nodes at the center of 



each plate. 



Basal plates within the cavity of the calyx and extending as 

 high as the base of the free arms. First primary radials are 

 entirely within the basal concavity. Second primary radials 

 short, quadrangular, two or three times as wide as high. 

 Third primary radials, short, pentagonal, axillary and each 

 supports on one of the superior sloping sides four secondary 

 radials. and upon the other a single secondary radial which is 

 axillary and bears upon each upper sloping side four tertiary 

 radials. by which arrangement, there are three arms to each 

 ray. There are. therefore, fifteen arms in this species, and 

 fifteen ambulacra] openings to the vault. 



The azygous area is like the other areas. The first inter 

 radials are somewhat elongated, have nine sides and are 

 broadly truncated above for the second interradials. Instead 

 of a centra] node, on each plate, there is a central excavation. 

 from tlie margin of which the plates are radiately sculptured. 

 The second plate is shout one fourth as large as the tirst and 

 it is followed by two small plates in the third range that 

 unite wit h the plates of the vault. 



The vault is subcorneal and bears a subcentral orifice at the 

 mil. Probably the orifice might be said to be at the top 



Of the proboscis, but the proboscis is not the sixteenth of an 



inch high, and hence, appears only as a sligbi elevation for 

 the azygous opening. The sutures on the vault, in our speci 

 mens, are so badly obliterated that it is impracticable to attempt 

 : i describe the plates. There are four ovarian slits between 

 each radial -cries, and two between each of the ambulacra] 

 openings, which arrangement gives to this species forty ovarian 

 apertures 



