92 F. A. BATHER, CRINOIDEA OF GOTLAND. 



R s ; in a its width is 3 mm., its height 2.5 mm.; in b its width is 2.75 mm., its height 

 3.25 mm.: the superradial is almost a right-nngled triangle, with convex sides and concave 

 base; in a its width is 3.5 mm., its height 1.6 mm.; in b its width is 3.75 mm., its height 

 2.25 mm. 



Large radials: These are 8-sided, being bounded as follows. — (1) by articular 

 facet, including part of IIBr t , with a concave curve, in a 3.5 mm., in b 4.75 mm.; (2) by 

 post. or r. ant. R', in a 2.75 mm., in b 2.25 mm.; (3) by outer basal at corner of hinge, 

 in a 0.5 mm., in b 1.25 mm.; (4) by the left basal (i. e. the hinge-line), in a 1.5 mm., 

 in b 2.75 mm.; (5) by 1. ant. R J , with a coneave curve, in a 3.5 mm., in 6 3 mm.; (6) 

 by the corresponding large radial, in a 0.5 mm., in b 1.25 mm.; (7) by 1. ant. R s , with 

 a concave curve, in a 2.5 mm., in b 3 mm.; (8) by the corner of 1. ant. IBr x , in <t 1 

 mm., in b 1,4 mm.: the extreme height of this plate is in a 5.25 mm., in b 7 mm. Side 

 1 is at rather less than a right angle to side 7, and at a slightly obtuse angle to side 2- 



The r. ant. R' does not abut on the stem; it may touch Ilax of ant. ann; it touches 

 x and usually only a very small part of the T-piece. The rad i an al corresponds. These 

 plates are longer and narrower than in previous species; the suture between them and the 

 large radials is mnch curved, and in b is härd to distinguish. 



The T-piece is extremely small; in a its outline cannot be distinguished, but in b 

 a small triangulär plate is scen between x, r. ant. B, and r. ant. R; this is the remains 

 of one wing of the T-piece, which probably formed a very thin strip, slightly expanded 

 at its ends. 



Anal strnctures: x rests on the remains of the T-piece and on r. post. R' and 

 r. ant. 11'. It is to be noted that these latter are still separated from one another, in a 

 by 2.25 mm., in b by 3.75 mm., a fact which distinguishes this species from Halysiocrinus. 

 x and the two succeeding plates are much as in C. tucanus, but the triangle formed by 

 them is a little wider. 



Arms: 1. ant., — 8 ossicles are preserved in a, only 1 and some fragments in b. 

 The first brachial is practically four-sided, but, as it rests by its lower corners on the 

 large radials, one or both of these angles may be truncate; its height in a is 2.25 mm., 

 in b 3 mm.; its extreme width below is in a 4.1 mm., in b 5.5 mm.; its width above is 

 in a 3.1 ram., in b 3. t; mm. Subsequent ossicles are fairly regular, about as high as wide, 

 slightly moniliform, being more elevated along the middle line. 



Ant. and 1. post. arms. — ■ There is only one primibrach, and in this point the 

 species differs from all other Gotland species: this is a low triangulär plate, with a rather 

 obtuse angle; it rests on its own large radial and on the adjacent inferradial, and abuts 

 on x\ in a the length of its base is 4.5 mm.; its upper slope supporting the axil-arm is 

 2.5 mm. long; its outer slope supporting Ilax is 3.75 mm. long. Succeeding mainaxils, 

 5 or (i in cither arm, are of essentially the same strueture as in C. tucanus, but the lower 

 or inter-facet surface is turned at a sharper angle to the upper surfaee. Only the large 

 outer or adanal armlets of the axil-arms are seen on the exteriör; these lie parallel to 

 one another and to the 1. ant. arm, from which they gradually deei-ease in size. In each 

 axil-arm the second and fourth plates are seen from the slant of their sutures to be 

 axillary, and a close inspectiou shows a minute triangulär plate on the inner or abanal 



