176 PROCEEDINGS OP THE ACADEMY OP [1886. 



b. Oraphiocrinites. 

 GRAPHIOCRINUS De Koninck, Rev. i, p. 121. 



GraphioGi'inus has a bilateral symmetry, and is in some 

 respects higher developed than the preceding genera, owing to 

 the absence of the azygous piece. It has onl}' an anal plate, and 

 this is small and placed between the radials, resting upon the 

 truncate upper side of the posterior basal. The ventral sac is 

 cylindrical, and in Graphiocrinus rudis composed of longitudinal' 

 rows of subquadrangular pieces. We have not been able to 

 examine the tube in other species, and hence are not aware 

 whether the arrangement of these plates is of generic value. The 

 species heretofore referred to Graphiocrinus have but a single 

 brachial and ten arms ; we have, however, in our collection an 

 undescribed species with only five arms. 



No additional species have been described. 



BURSACRINUS M. and W., Rev. i, p. 123. 



Syu. Synyphocrinus Trautschold, Bull., 1880. 



In a paper " Ueber Symjphocrinus,^^ Trautschold described a 

 new species from Moscow, for which he proposes the above 

 generic designation. He asserts that it differs from PoteiHocrinus 

 and allied genera in having " pentagonal, roof-like second radials, 

 and these provided along the ventral side with two thorn-like 

 processes, separated by the tentacle furrow ; " that the third 

 radials had similar processes and re-entering angles, overlying 

 and covering the roof of the preceding plate; that the upper 

 truncate side supported two bifurcating plates ; that the species 

 had no pinnules, and that the vault rested upon the thorn-like 

 extensions of the third radials. We think Trautschold misunder- 

 stood his specimen. From his own figures and descriptions it is 

 evident that the calyx, as in other Fistulata, contained a single 

 radial, and that all succeeding plates were free, and true arm plates. 

 His " second radial " is grooved for the reception of the " tentacle 

 furrow," and, as shown by its form, a regular bifurcating plate, 

 his remarkable " third radial " represents the two proximal arm 

 plates, placed aside of each other, given off from the plate below. 

 That pinnules were present in this species is shown even by the 

 figure in which their faces are plainly represented. The processes 

 at the inner side have no generic value, they are in connection 

 with the articular faces of the plates, and are found, more or less, 



