1 IS F. A. BATHER, CRINOIDEA OF GOTLAND. 



The Arms are generally of the same character as in C. longimanus and C. acino- 

 tubus; but the different series have rather a larger numbér of ossicles and are verv straight. 

 Tlie brachials are hardly at all rounded; in section they form a half-ellipse, and are a 

 little higher than wide, with a rather broad ventral groove. The axial canal is separate. 



The ossicles, when well-preserved, have a fine shagreen ornament. 



The covering-plates are typically of the same structure as in C. acinotubus, but 

 even more massive than in that species. The elements c 1 , c 2 and i can be distinguished 

 (tigs. 249, 250, 255), at all events in some specimens. Occasionally narrow side-plates 

 (? adambulacral) alternate with the covering-plates proper (Iconogr. Tab. XXVI, tig. 5 b). 

 When the ventral snrface of the arm is viewed directly from above, it often happens that 

 no part of the brachials can be seen, since the covering-plates actuallv bulge out beyond 

 thcin. In other cases a small portion of the brachials is visible ou either side of the 

 covering-plates. The number of covering-plates to a brachial is 1 or l 1 /-.- The covering- 

 plates often have a shagreen ornament like that of the brachials (fig. 254); often, however, 

 they are transversely ridged (Iconogr. Tab. XXVI, tigs. 4, 5), an appearance Avhich mav 

 have originated the erroneous idea, that these covering-plates represented either primitive 

 or degenerate pinnules (see Iconogr., Explicatio Tab. cit.; Wachsmuth and Springer, Rev. 

 1, 24, 25, and Proc. 1879, pp. 247, 248, 305; P. H. Carpenter, Challenger Peport. 

 Stalked Crinoids, pp. 65, 66; and F. A. Bather, »Brit. Foss. Grin. VIII», tom. cit. p. 224). 

 Carpenters suggestion {op. cit. ult. p. 84, footnote) that these covering-plates were anara- 

 bulacral plates protecting the gonads would of course not have been made, had he been 

 aware of their true structure. 



In specimen <h the type of Angelins C. zonatus, the covering-plates are a little 

 narrower than in ordinary specimens of C. ramosus, and each plate extends almost or 

 sometimes quite to the opposite side of the ventral groove. c 1 and c 2 are distinct. A 

 small portion of the brachial is visible when the arm is viewed from the ventral surface 

 (tigs. 259, 260). 



IBr are stated in Axgelin's diagnosis to be 3 or 4; they are also said to be 4 in 

 C. zonatus; and 4 or even 5? are represented in the tigure of C. alutaceus (Tab. XXIII, 

 10). This is a point of no importance; but, as a matter of fäet, no specimen of this 

 species has yet been proved to have 4 IBr: it is quite impossible to distinguish the num- 

 ber in specimen d, while the drawings of specimen b are considerably restored, and what 

 is not restored is incorrect. 



Anal struetures: x is hexagonal and shaped as in other species; but the suture 

 between it and the ensuing median plate is rather more curved, with the concavity di- 

 rected downwards. 



The Ventral Sac is narrow and tubular, with a lumen small compared with other 

 Cyathocrini (tig. 252). The length of the sac is unknown, but it was apparently short, 

 and in many cases is only represented in the fossils by an irregular jirotuberance (Text- 

 tig. 20, spec. b). The plates of which it is composed are irregular both in size and shape. 



The Tegmen is well known from specimens b, c and It (Text-tig. 20), which have 

 all been figured by Angelin to show this structure, and of which the two latter are re- 

 presented willi great accuracy in Plate IX, tigs. 1 and 2 respeetively, ut' Messrs. Waciismiiii 



