ALCYONAKIA. 



By J, Arthur Thomkon and Doius L. MAfKiNNON. 



(Plates Ixi-lxxjcii.) 



The collection of Alcyoiiarians niude by the " Tlielis " includes 

 thirty-five species, of which thiitcen are new, — alargepioportion. 

 When the specimens are arranj^ed in systematic order, it is seen 

 at a glance that tlie collection has a very detinile character, 

 namely, the proportionately lar<;e numher of Isidie {e.g., six 

 species of Mopsea, four new) and of Prinmoidre (e.g., five new 

 species of Plumnrella). These Isid and Prininoiil colonies are 

 extraordinarily beautiful, and their supeificial resemblance to 

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

 fication that numerous specimens of some of tlie new species have 

 been preserved, so that it was possible to make sure that one was 

 not dealing with iiulividual variations. 



Another feature of the collection is the frequent occurrence of 

 encrusting colonies of Alci/onium (Erythropoflium) ineinbra- 

 iiaceuin and A. replaiis described b}' Kiikenthal, which grow over 

 Gorgonid axes in a very misleading fashion. It is not too much 

 to say that an unprejudiced observer, wlio had not seen tlie real 

 state of affairs exposed in unmistakeable cases, would de.scribe 

 these Gorgonid axes encrusted with Enjlhropodiuvi as peculiar 

 Axifera. 



LIST OF SPECIES ^ 



Order I. STOLONIFERA, Hickson. 

 Family CORNULARIIDiE. 

 Clavulariajlava, Hickson. 



Order II. ALCYONACEA, VerrilhK'ro. p»rte). 



Family A LC YO N I D jE. 



Alcyonium (Erythropodiuia) membra naceum, Kiikenthal. 



,, „ reptans, Kiikenthal. 



* „ etheridgei, sp. uov. 



^ Those that aru new are marked with an aateriik. 



