! 2 



Wrighi and Studer add to tlii^ description the character of the axis, which is really the 

 besl diagnostic feature of the genus. After quoting Verrill's definition they add: 



■ ro this may be added that in the structure of the axis there is a general resemblance 

 to th.a of relia". 



In spite ot' this "genera] resemblance", however, there is a very distinct difference between 

 the a\is of /' lla .nul that "t Euplexaura. In ;i cros-, section «'f a branch of a typical 



species of P lla the clear, h<>niy core is surrounded by ;i thick envelope which is composed 



<>t' .1 number of long, vermiform, white calcareous bodies enclosed in a casing of chitin. In a 

 similar section of Euplexaura no such definite structure of the axis is seen; but there is a 

 central core ,,i pure, translucent, horny material around which is a thick cylinder of horny 

 material extensively impregnated with lime salts. These latter sometimes scem to take the forra 

 of fibres, luit are nut nearly so distinct and white as the vermiform bodies of Plexaurella. 

 The axis of the latter genus is excellently well illustrated by Köixiker, Icones Histologie^, II, 

 plate XIV, fig. S. It has also been deseribed and figured by the present writer 1 . 



K ki NiiiAi has emended the definition of this genus in so satisfactorv a manner that 

 we ma) adopt his diagnosis, which is as follows: 



"Koloniën in einer bbene verzweigt. Polypen fast stets ohne gesondertc Kelche direkt in 

 das dicke Ccenenchym zurückziehbar. Polypen stets mit konvergierenden Reihen von S])indeln 

 bewehrt, unter denen horizontal angeordnetc liegen. Die Rinde enthalt an der Oberflache dicke, 

 meist ovale Spindeln und Doppelspindeln, die dicht mit grossen Warzen besetzt sind, darunter 

 n kleinere, schlankere Spindeln mit regelmassigen Dornengürteln. Achse fast stets etwas 

 verkalkt und wenig biegsam. Die Farbung samtlicher Arten schwankt zwischen weiss, gelblich 

 und hellbraun". 



The type of the genus Euplexaura is Euplexaura capensis Verrill. The other known 

 species are Euplexaura pinnata Wright and Studer, E. rhipidalis Studer, E, parciclados Wright 

 and Studer. /:'. anastomosans Brundin, E. curvata Kükth., E. robusta Kükth., E. crassa Kiikth., 

 E. abietina Kükth., E. sparsiflora Kükth., E. erecta Kükth., E. albida Kükth., E. braueri Kükth., 

 /;. paria Kükth., and the new species about to be described. 



i. Euplexaura rubra new species. (Plate III, figs. 3, ,,<?: Plate IV, fig. 7). 



Stat. 164. 1 42'. 5 S., I30°47'.? \'.. Near New Guinea. 32 meters. 



ilony incomplete, about 8 cm. long. The basal part is lacking, and it appears that 



we have but the terminal portion of the main stem. or large branch, giving off two small 



il branches on one side, and one on the other. The stem and branches are round in section, 



r of the tonner being 2.5 mm. and of the branches about 1.5 mm. The calyces are 



rather prominent for this family, and are equally distributed on all sides of the branches. 



The individual calyces are coninal in form, a typical one measuring about 1 mm. in 

 ight and 1.4 mm. across the base. The poKps are compleiely retractile, the summits of the 



illetin from the Laboratories "f Natura] History of the State University ol I 



. 8, 9 and 10. 



