8 TORSTEN GISLEN, CRINOIDS. 



Are C. pectinaia and purjmrea really differentiated with regard to this character? 



To answer this question I have very carefully examined the arrangement and 

 grouping of the cirri on the specimens that have been at my disposal. During my 

 examination I have come to the conclusion that the two types are not without inter- 

 mediate forms and that the type purpurea is hardly to be estabhshed as a species, 

 at least if the differentiation is founded upon the arrangement of the cirri. 



In the following I have shown with vertical lines the group arrangements. 

 (They thns correspond to gaps in the row.) As soon as 2 or, at the most, 3 C:i 

 liave entered into a group it extends ont from the interradial compartment, to which 

 it is limited in the purpurea-i orm. 



Roman numerals signify the number of the C:i, arabic ones indicate the seg- 

 ment-number. R = Radial area. IR = interradial. 



Specimen 1 (Station 2) C. XVIII (of those XII empty joint-cavities) 12, 11, 

 — | XI, 12, — (young R., regenerating in an old joint-cavity?) — , 13, — , — , etc. 

 in a continuous row. 



Specimen 2 (St. 2) C IX (a small specimen, the arms 40 and 25 mm resp., 

 ptirpurea-type) j 11, 1111 (young)lOj 11 j 12, 12 j 10 (young, indistinctly segmented) 11 . 



Specimen 3 (St. 3) CXI (of these V ones broken at the basis. Tendency 

 to purpurea-arrangement. Empty joint-cavities radially) | 12, 11 (young, ventrally of 

 the C-row \ 11 j 11 j 11 .! 11 1. A psendo-purpurea. 



Specimen 4 (St. 5) (a small specimen) C. XIV j 11 (young IR) 10 9, 10,9 11 

 (juv., IR) 11, 10 (juv., IR), 10 (very young, R) 10 (young R), 11, 11 (young, R) — 

 (very young, IR) 11 j. 



Specimen 5 (St. 5) C XIV (V of these old with coloured stripes crossing 

 each other — in 3 cases R.-ly arranged, in 2 cases evident! y forced out of their 

 place by the outgrowing C. The rest of the C. unstriped) 10, 10, 10, 10, 10, 10, 9 

 (young) 9, 10, 9, 9, 9, 9, 9. 



Specimen 6 (St. 5) C. X 11, 13 (R) 1 12, 10, 12 13, 11 i 10, 11 — j. In the groups 



I, 4 and 5 pwrpwrea-arrangement. On the remaining places no interradial concen- 

 tration. 



Specimen 7 (St. 5) (large specimen) C XV 11, 11 11, 11, 11 11, 11, 11; 



II, 11 1 11, 10, 10 10, 11 |. Two interradial groups, one with 2 and one with 3 C. 

 The fixing places of the remaining C:i form a continuous row, but are by the animal, 

 when it was still in life, bent together in groups that are usually situated inter- 

 radially. 



Specimen 8 (St. 12) C XVIII (of these III small ones) 11, 15, 10 11 (young) 

 11 (very young) i 12, 11, 10 (young), 12, 11, 12, 11, 11 (young) 12, 10, 11 12, 12 . Thus 

 2 /r. of the row with pitrpurea-Sbrrangement. 



Specimen 9 (St. 12) C XVI (II empty joint cavities) 12 (young, ventrally), 

 11, 10, — , 10, 11, -, 10, 10, 11, 10 9, 11 10, -, — . 



Specimen 10 (St. 12) C XVI (one small C) 11, 12, 12, 11,— (young, grows 

 R-ly) 12 (young), 11. - (young R), — , _, — , — , 12, 12, 13, — (young R) . Large 

 specimen. 



