84 CALYCOSILVA CANTHARELLUS. 



and size; the number of them on each of the six main-rays is, however, by no 

 means always the same. The end-rays are 1.5-2 fi thick at the base, and arise 

 steeply, sometimes at nearly right angles, from the main-rays. Farther on 

 they curve inward, towards the continuation of the axis of the main-ray to which 

 they belong. Distally this curvature rapidly decreases and the end-part is 

 for a smaller or greater, usually a very considerable length, either quite straight 

 or only slightly curved, or irregularly bent like an oak-branch and knotty in 

 appearance. Onychhexasters with end-rays thus bent have been chiefly found 

 in C. c. var. rnegonychia (Plate 4, figs. 2-4, 14, 17). In all regular onychhexasters, 

 whether large or small, the centrum, the main-rays, and the proximal parts of the 

 end-rays are nearly identical in shape and have the dimensions given above ; the 

 great differences in these hexasters observed are entirely due to differences 

 in the degree of longitudinal development of the distal straight end-parts of 

 the end-rays. In the smallest onychhexasters observed (Plate 3, fig. 21) this 

 distal straight part is quite insignificant and hardly distinguishable. The 

 larger the onychhexaster is, the longer and the more conspicuous does this part 

 of the end-ray become (Plate 3, figs. 22-27; Plate 4, figs. 2-7). The end-rays 

 are cylindroconic, attenuated distally. This attenuation is slight and very 

 much the same in all end-rays, however long they may be. The consequence 

 of this is that the thickness of their distal ends is in inverse proportion to the 

 length of the end-rays; greatest in the shortest, and smallest in the longest. 

 In the small onychhexasters, 39-45 yu in diameter, of C. c. var. helix, the end-rays 

 are 15-18 /u long and 1-1.8 m thick at the end; in the largest onychhexasters, 

 80-88 IX in diameter, of the same variety the end-rays are 34-41 ^ long and only 

 0.8-1 M thick at the end. In the larger onychhexasters of C. c. vars. simplex 

 and megonychia the same inverse relation between the length and terminal thick- 

 ness of the end-rays is observed. The angles between the chords of end-rays 

 arising opposite each other from the same main-ray are correlated and in inverse 

 proportion to the size of the spicule and the length of the end-rays. In the small 

 onychhexasters, 39-45 m in diameter, of C. c. var. helix, these angles are 70°-90° ; 

 in the large ones, 80-88 m in diameter, of the same variety 59°-77°. 



The end-rays bear numerous small recurved spines along their length 

 (Plate 3, fig. 28; Plate 4, figs. 9, 10, 16) and one to five large spines at the end. 

 The former are largest and most conspicuous in the smallest onychhexasters 

 (Plate 3, fig. 22) ; in the large onychhexasters they are smaller. Their size is, on 

 the whole, in inverse proportion to the length of the end-rays and the size of 

 the whole spicule. In the smallest onychhexasters the terminal spines are 2-3 ^ 



