86 F. A. BATHER, CRINOIDEA OF GOTLAND. 



Calceocrinus tucanus, n. sp. 

 Plate III, ftgs. 105—107. 

 Diagnosis. 



Proportions of cup are, — height 1; width 1.27; width at hinge 1.09; thickriess 0.872. 

 Cup scen from 1. ant. radius roughly quadrangular, low; witb upper angles rounded off; 

 constriction very slight. 1. ant. R* and Ii' separated. T-piece biconeave, widening altove; 

 rests by its sides on the inferradials. x niore than twice as wide as high; rests on T- 

 piece and, by its corners, on inferradials. 1. ant. arm not much stouter than the larger 

 branches of the primaxil-arms; apparently simple. Ant. and 1. post. arms have mainaxils 

 u]> to Vax or Vlax. IBr 2. Axil-arms follow the normal type; their larger branches 

 gradually decrease in size; abanal branches small and largely hidden by adanal /?Br and 

 yl>v, l>ut can be distinguished even when arms are closed; their sides are compresscd and 

 long in proportion to width. Axillaries after «ax and /?ax hardly at all nodose. Hinge 

 witb cross-processes distinct. Shagreen ornament very slight. Stem-ossicles show clear 

 curvature in proximal region. 



This species is founded on two specimens one of which (a) shows the arms and slem 

 and cup more clearly, while the other (f>) shows the anal area, but is much weathered 

 and broken about the cup and arms. The latter specimen approaches the structure of 

 C. pugil in the arms, while the former specimen is nearer C. tenax. Bolh specimens, 

 howevcr, resemble one another in the shape of the cup and in the anal area, and may 

 well be placed together in a single species. 



Description. 



General appearance of erown less massive and less irregular than in C pugil. In 

 the closed state, as viewed from either the ant. or 1. post. radius, the crown is enclosed 

 by two gentle curves, of which that on the side of the 1. ant. arm is more marked. The 

 stem arises at about right angles to the axis of the crown, and curves gently round. 

 Thus the whole appearance remirids one of a toucans head witb its enornmus bill, and 

 this has suggested the trivial name. 



Dorsal cup: The general outline, as seen from 1. ant. radius, is quadrangular and 

 low, with the faintest trace of a constriction; the upper angles are rounded off by the 

 facets of the radials, which slope more than in C pugil. The measureiuents are, — height, 

 5.5 mm.; width, 7 mm.; thickness 4.8 mm. The height of the cup is to the length of the 

 arms as 1 1 to 48, les^s than in C. pugil. The 1. ant. and r. post. faces are at an angle 

 of about 18°, i. e. much less than in C. pugil. 



P>ase has a width of 6 mm.; a height of 2.5 mm., i. c. rather less in proportion 

 than in C. pugil. 



BB. — 3 observed. Left basal is shaped much as in C. pugil, but it is a little 

 doubtful whether the stemward tongue quite reaches the stem, at least on the surface. 

 In one specimen this fused basal shows doubtful traces of the original suture. 



