34 



F. A. BATHER, fRIXOIDEA OF GOTLAND. 



the absence of any ovoid curve. The sub-triangular seetion, due to the large part taken 

 in the cup by only three plates, is shown well in text-tig. 8, which also shows the relative 

 thinnesa of the plates. 



The Arms are triangulär in seetion (text-tig. 10 and 11), with a deep semicireular 

 groove on the inner side. In the seetion (text-fig. 11) the eovering-plates are scen some- 

 what disturbed. The diagrammatic text-figure 10 is eonstrneted from the evidence of all 

 three known specimens: the covering plates doubtless alternated as shown in Follmanx.s 

 drawing of Calycanthocrinus (oj), rit. Taf. II, fig. 2 c); there appears to have been a slight 

 groove or rebäte on either side in which they hinged. The first braehial is short and 



1. ant. Ray 



Ant Ray 



r. ant Ray 



Fis. 10. 



1. post. Ray Anal tu, ' e r. post. Ray 



Fisr. 11. 



Strvctvre of Pisocrinus pocillm 



Fig. 8. A seetion of tlie eup just above the level of the basals. X 8 diam. The asterisk shows the posterior 



interradius. 

 Fig. 9. Diagram of the posterior and right posterior plates. Considerably enlarged. 

 Fig. 10. Reconstructed seetion across 2nd braehial, with the eovering-plates in position. Semidiagrammatic and 



inueh enlarged. 

 Fig. 11. Seetion across the distal ends of the 2nd hraehials, showing the eovering-plates somewhat disturbed. A 



plate of the Anal tube with its eovering-plates is scen in the middle. X 28 diam. 



wide, the seeond brachials 4 or 5 times as long as wide; more are not preserved in 

 entirety. 



Anal struetnres: Anal x (text-tig. 9 and Pl. I fig. 20, 23) rests on the process 

 formed by the two posterior radials, but is chiefly supported by r. ]iost. K; it rests against 

 the adjacent lirst brachials, and passes inwards between the seeond brachials. It apparently 

 supported a series of ossicles hardly to be distinguished from tliose of the arms externally, 

 with a similar ventral groove a very little larger, and with small eovering-plates on the 

 ventral side. All these details are shown in text-tig. I lj but the eovering-plates are pressed 

 into the groove, as is also the ease as a rule with the eovering-plates of the arms. 



