TOKSTJäN G1SLEN, CKINOlDS. 



guishing thc species in the milberti-growp. Both the former ones I have referred to 

 the same species; as to the latter group I am of the same opinion as Reichen- 

 sperger that A. discoidea A. H. Clark is not to be distinguished as a species and 

 consequently I have joined the synonymous lists of both into one. 



Both in the description of Comatula pectinata and Amphi?neira milberti, but 

 especially in Oligometra adeonce, I have taken great pains to contribute to the sta- 

 tistics of variation as to the number of the cirri and of the cirrus-segments. In the 

 last-mentioned species the number of the segments and the length of the proximal 

 pinnulse have been objects for my especial attention and I have fomid out here with 

 regard to the number of the cirri and cirrus-segments (cirrals) that the variability 

 even in specimens of about the same size is rather great, a fact that ought to make 

 us very cautious in establishing new species on the basis of these characters. 



In demonstrating the ramifications of the arm and the distribution of the 

 syzygies 1 have used the suggestion that Minckert has applied in his paper of 1905, 

 but I have modified his idea and simplified his notation so that the scheme is more 

 easy to use. More detailed information about this will be found at the explanation in 

 the scheme under C omaster typica. 



As to the abbreviations and technical terms I have previously applied the 

 terminology that Bather and other crinoid students after him have used. 



R. (the radial) is thus the first ossicle of the arm, often hidden by Cd (Centro- 

 dosale). After the radial there are almost always two primibrachials, which are denoted 

 by I Br 1 and I Br 2. The last mentioned is an axillary carrying on its distal sur- 

 face two secondary arms. If the animal has ten arms these subdi visions are unra- 

 mified, otherwise after the I Br 2 the secundibrachials (II Br:s) follow with the 2 d > 

 the 4 th or in some cases the 3 d segment forming an axillary. On this one a new divi- 

 sion series, the tertibrachial (III Br), may possibly arise, then perhaps a IV Br series 

 and so on. The segments of the armbranches that are not further divided are signi- 

 fied as Br (brachial) with the number of the segments counted from the last axillary. 



The number of the cirri (C.) is written in roman figures, the number of the 

 segment in arabic ones. 



The pinnules (P.) are denoted on the outside of the arm by ordinals, on the 

 inside they are given the letters P a , P b , P c etc. 



Thus I have indicated the pinnula on II Br 2 or on Br 2 as Pj under all circum- 

 stances, not, as has been hitherto customary, in the former case as Pl> (distichal 

 pinnula); this has been done so as to get a corresponding notation and to avoid the 

 same pinnula in one arm-division for instance being called Po, on another arm with 

 developed »palmaria» (III Br) being named Pr. Finally I have indicated synarthries 

 by hyphens, syzygies by the plus sign. 



Before passing on to the actual descriptions of the species I shall enumerate 

 the localities from which the collection has been made, giving at the same time a 

 complete list of the species which have been taken at each different place. 



