1886.] NATURAL SCIENCES OF PHILADELPHIA. 101 



The arms he described as bearing " siibelformige Teiitakeln " 

 (pinnules), and in the description of Cupressocrinus gracilis he 

 gave a grapliic account of the articular facets of the radials. 

 These, according to his statement, extend deeply inward, so as 

 to diminish largely the width of the visceral cavity, which at the 

 upper end is reduced to one half the depth of the facet. Behind 

 the " Nahrungscanal " (axial canal), he says, there extend out 

 two diverging muscular extensions, which connect by a cross- 

 piece, abut against their fellows of adjacent radials, and form 

 together a star-shaped figure, composed of five pairs of leaves. 

 The ventral surface, therefore, according to Goldfuss, consists of 

 five coalesced muscle-plates, and not, as was supposed by 

 Roemer, Schultze and Zittel, and heretofore by ourselves, of an 

 independent plate or appai'atus, peculiar to this genus. F. 

 Roemer described it as a cribriform calcareous plate, in form of a 

 five-leaved flower. Schultze speaks of it as five delicate plates, 

 which join radially, four of them equal, the fifth one different 

 and containing the anal opening. He calls it a consolidating 

 apparatus, constituting a part of the inner body, and not portions 

 of the outer test; pierced by various openings, through which 

 the blood-vessels, axial canals and genital organs passed into the 

 arms. A similar view was held by Zittel, who stated : " There is 

 in the interior of the calyx, at the base of the arras, a peculiar 

 annular, so-called consolidating apparatus, composed of five 

 large interradial (oral) plates, with a round (mouth) opening at 

 the centre." Also, De Loriol mentions a peculiar " Consolida- 

 tions-apparat, qui a ete rapproche des hydrospires." 



The views expressed by us, Rev. I, p. 12, to which De Loriol 

 alludes, differ from those of our co-laborers. We held that the 

 so-called " consolidating apparatus " was composed of five oral 

 plates, which we thought stood in connection with five pairs of 

 h3^drospires. To this interpretation we were partly led by a cer- 

 tain superficial resemblance, but principally by the fact that 

 Roemer, Schultze and Zittel, who had access to the splendid col- 

 lections fi'om the Eifel, all agreed that the plates in question were 

 interradial in position. If this had been true, nothing could 

 have been more natural but that these plates should be struc- 

 turally identical with the deltoids of the Blastoidea, and the 

 interradials of the Gyathocrinidae, which were then held by us to 

 be oral plates. 



