ALCYONARIA. 



By J. Arthur Thomsox and Doris L. Mackinnon. 



(Plates Ixi-lxxxii.) 



The collection of Alcyonarians made by the " Thetis " include s 

 thirty-five species, of which ihiiteen are new, — a largepioportion. 

 When the specimens are arranged in systematic order, it is seen 

 at a glance that the collection has a very definite character, 

 namely, the proportionately large number of Isidse {e.g., six 

 species of Mopsea, four new) and of Primnoidre {e.g., five new 

 species of Plumarella). Tliese Isid and Primnoid colonies aie 

 extraordinarily beautiful, and their supeifioial resemblance to 

 large fronds of Sertularians is striking. It is a matter for grati- 

 fication that numerous specimens of some of the new species have 

 been {ireserved, so that it was possible to make sure that one was 

 not dealing with indivichial variations. 



Another feature of the colhction is the fi'equent occurrence of 

 encrusting colonies of Alci/onixim ( ErythropodiumJ memhra- 

 naceum and A. reptans described by Kiikenthal, which grow over 

 Gorgonid axes in a very misleading fashion. It is not tt)0 much 

 to say that an unprejudiced observer, who had not seen the rtal 

 state of affairs exposed in unmistakeable cases, would describe 

 these Gorgonid axes encrusted with Erythropodivm as peculiar 

 Axifera. 



LIST OF SPECIES ^ 



Order I. STOLONIFERA, Hickson. 

 Family CORNULARIID^. 

 Clavtdaria jkiva, Hickson. 



Order II. ALCYOXACEA, F^rr/// (pro.: parte). 



Family ALCYONID^. 



Alcyonium {Erythropodium) niembranaceum, Kiikenthal. 



,, repUtns, Kiikenthal. 



* ,, ether idyei, sp. no v. 



1 Those that are new are marked wit!i an asterisk. 



