372 Wachsmuth and Springer—Paleocrinordea. 
specimens and the three-armed one from Erras. As to the 
absence of the small posterior radial, he thinks it may have 
been lost in the specimen. He attributes Volborth’s organ to_ 
mechanical causes and deems it to be of no value specifically 
or generically. According to his statement, the calyx bulges 
out and is torn up by rents and cracks, which follow all possible 
directions, forming small irregular plates, and that some of the 
cracks extend deeply into the surrounding plates (fig. 1 on pl. 
1). Schmidt explams the “Ausschnitte” between the arm 
joints in the Erras specimen as incidental breaks, which he 
attributes to the delicacy of the plates toward the articulation. 
othing is said about a difference between the two types in the 
form of the body. 
According to Carpenter, the last writer upon the subject, 
the cylyx of Barocrinus “consists of ten plates, which are 
arranged in two alternating rows without any indications of 
anal plates,” and he remarks—“ this does not agree at all with 
Billings’s analysis of the Hybocrinus calyx.” He says further: 
“ Berocrinus, if rightly described by Grewingk, represents to 
my mind an altogether different generic type,” and “ occupies 
a somewhat unique position among the Crinoidea. It is, per- 
haps, best regarded as a permanent larval form, which has only 
developed three of its five arms.” And he says of Volborth’s 
organ—“it struck meas possible that it may represent the 
anal opening, which does occupy a somewhat similar position 
between the radials and basals at one period of Orinoid devel- 
opment.” He also alludes to the triangular outline of the 
ealyx in Berocrinus, and the pentangular form in “ Hyboert 
nus,” which he thinks additional proof that the two are distinct 
types 
and radials; and the calyx has a different form. It has been 
stated that neither Grewingk, who gave a cross section of the 
