400 PROF. F. JEFFREY BELL ON THE [May 1, 



merit that the Byzygial mode of union makes the arms more 

 fragile at the points where it occurs, those who believe in the 

 efficiency of Natural Selection will not accept the view that this 

 doubling of the syzygies is of advantage to the possessor. 



I hope, therefore, that the peculiarities of this specimen (I will 

 not say of this species) may come under the notice of those who 

 work at Crinoids, and that material may be gathered sufficient for 

 us to make up our minds as to whether we have to do with an 

 individual eccentricity or a true character specifically distinctive 

 of its possessor. 



There remain to be noticed five bidisticbate species with more 

 than ten arms of which I cannot give full descriptions, as the single 

 specimens by which they are represented are not always well 

 preserved. Diagnoses, however, are possible. 



They may be thus arranged, in accordance with Dr. H. Carpenter's 

 scheme on pp. 211, 212 of the Report on the ' Challenger' Coma- 

 tula? : — 



A. Over 30 cirrus-joints i. Antedon vicar ia. 



B. 30 or less than 30 cirrus-joints. 



Cirri without definite arrangement. 



., " e | 25 cirri of 9 joints each ii. Antedon brevicirra, 



, s ii, 1 About 30 cirri of 16 smooth joints ... iii. Antedon jlavomnctdata. 



e- j f Faint spinous process on later cirrus- 



. ,, J joints iv. Antedon moorei. 



fl. n 1 1 Very broad spinous process on later 

 a ' [_ cirrus-joints v. Antedon ficldi. 



Antedon yicaria, sp. nov. 



Bidisticbate, with Mall-sided radials, strong pinnules, and about 

 30 cirrus-joints, of which the more distal are spiny. With so much 

 resemblance to A. macronema, it has shorter cirri (20 mm.) and 

 has numerous (30) joints. Arms probably about 25 in number. 

 Neither radial nor distichal palmars syzygial. Cirri white, arms 

 white with middle dorsal line of purple, pinnules purplish. 



Spread 100 mm. ; diameter of deeply incised disc 4 mm. 



Macclesfield Bank, 30-40 fms. 



Antedon breyicirea, sp. nov. 



Bidistichate, with flattened sides to brachials, 25 cirri of 9 joints, 

 rather more than 40 arms, and a long first pinnule. 



Colour light brown. 



Macclesfield Bank, 20-35 fms. 



This species is so much broken that I should not have described 

 it did I not wish to call attention to the short cirri set at the edge 

 of the disc, recalling in every way the cirri of an Actinomct ra . 



Antedon flayomaculata, sp. nov. 



Bidistichate, with (in the single known specimen) exactly 20 

 arms ; about 30 cirri, with 16 smooth joints, and the centre of the 



