182 F. A. BATHER, CRINOIDEA OF GOTLAND. 



The Arms are no1 preserved; 1 m1 there is sometimes to be seen a low first primi- 

 brach, which is not axillary (fig. 202). 



Anal structures: x is hexagonal and quite aormal; it supports a small median 

 and two lateral plates (tig. 202). One specimen from Wisby lins no anal plate at all, nor 

 (-tu tlie position of the posterior interradius be inferred. 



There cannol be much doubt that soine small ventral tubes, found along with the 

 calyces of the species, belong to it (tigs. 205, 206). They are of the same character and 

 size as the fragmentary remains of a tube still attached to the calyx in nianv instances. 

 The largest fragment is apparently complete, as it spreads out below where it joined on 

 to the tegmen; it is 9 mm. high; at the base it is 5 mm. in width transversely, and 

 ■l.i mm. sagittally; abont half-way up it has increased 0.2 mm. in transverse, and 0.7 mm. 

 in sagittal diameter; above this it curves in gently to a rounded point. It is composed 

 of 9 longitudinal rows of fairly thin hexagonal plates, which alternate with one another: 

 at the distal end these plates decrease in size, and one or two are here absent. Another 

 specimen shows that some of the rows end before quite reaching the distal extreinity. 

 All the specimens consisted of 9 rows in their proximal region; in one small specimen, 

 however, many of these die out at a rather greater distance from the apex than is the 

 case in the other specimens. Not one of the specimens is completely closed at the sum- 

 mit; and, although the exact arrangement of the plates cannot be made out, still it seems 

 pretty clear that there must have been some sort of flexible or sphincter-like opening. 



The Tegmen is often well preserved (fig. 201). There is a large madreporite. 

 The four deltoids are small, but larger in proportion in the young. The greater part of 

 the tegmen is occupied by small plates partly ambulacral and parti}- anambulacral. The 

 covering- plates extend for a short distance över the sides of the radials. A good drawing 

 of the ventral surface of the abnormal specimen named C. Icevis has been given by Messrs. 

 Wachsmuth and Springee in their paper on the Perisomic Plates x ), reproduced in text- 

 ligure 19. Concerning it they remark, »the resorption of the orals was apparently com- 

 plete, and their place is occupied by irregular covering pieces, which join in the center. 

 Farther out the ambulacra have well defined side pieces, and small covering plates close 

 the food grooves.» In the same place they remark, »The specimens .... which Angelin 

 referred to C. Icevis are either distinct species, or one of them is in a more advanced 

 stage of growth». The former, as wc have seen, is the case. 



The Stem is round, and composed of rather low ossicles alternating in height; the 

 liigher ones also project slightly. The articular surfaces are radially striate and the lumen 

 quinquelobate. 



Ornament: the plates of the dorsal cup mav be quite smooth, as in the specimen 

 named C. Icevis (fig. 204); or they may be in auy condition between that and coarsely 

 granulate (tig. 19'.)). r P 1 1 e grämdes tend to be produced especially round the börders of 

 the plates, and thus arises a line of granules more or less coalesced, as in the type- 

 specimen of C. monilifer (ligs. 202, 203); so regular a line of granules is however tpiite 



') Proc. Ara<l. Nat. Sci. Philadelphia, vo\. fur 1890, l'l. !\. (ig. 3, p. 356. 



