36 THE VOYAGE OF H.M.S. CHALLENGER. 



The material whicli I was able to place at Dr. Erdmann's disposal was derived 

 partly from the Bonn Museum, partly from the Triton expedition, but chiefly from 

 the Challenger collection. For the descriptions of the Challenger Zoanthese I 

 give here short extracts from his Memoir,' for the accuracy of which I can vouch, as 

 the whole investigation was carried out under my direction. I have achieved, what he 

 omitted, in identifying as far as possible the forms obtained with species previously 

 described, and, where that was impossible, have introduced new names, and have 

 reduced the diagnoses of species to shorter and more precise terms. 



Family 12, ZoANTHiDiE. 



Genus Zoanthus, Cuvier (pro parte). 



Integument not incrusted ; coen en chyme stolonar, with an occasional tendency to 

 lamellar extension ; sphincter difi'erentiated into upper and lower sections ; mesenteries 

 arranged on the microtype. 



Zoanthus dance (?), Le Conte (PI. I. fig. 1). 



Polyps with fleshy body- wall, the larger borne on a stalk-like extension, and 

 arranged closely together on reticulately branching stolons ; approximately fifty 

 tentacles arranged in two cycles. 



Habitat. — Bermuda Islands ; shallow water. 



Dimensions-. — Of the individual polyps — height, 0-5-2 -5 cm.-; breadth, 0-3-0 -5 cm. 



This animal, which I refer with considerable reserve to Zoanthus dance, is identical 

 with the Zoanthus which I have already described. To that description I can add the 

 following points, based on Erdmann's researches : — 



1. The colony grows on a foundation of rock in such a manner that the upper ends 

 of all the polyps lie in the same plane. As the foundation is irregular, the individual 

 polyps must be of unequal lengths, a result of which is that those animals which 

 correspond to hollows in the foundation are produced posteriorly into a kind of stalk, 

 distinguished from the body proper by a constriction, and by the thinner consistence of 

 the body-wall. 



2. A peculiar attachment of the cuticle to the body-wall, and one perhaps more 

 widely distributed among the Zoanthese, is efi"ected by mesogloeal processes which 

 perforate the epithelium and are inserted on the cuticle. 



3. The colony investigated by Erdmann was sexually mature ; ova and testicular 

 follicles occurred in the same mesentery. 



Erdmaim, Ueber einige neue Zoautheen. Bin Boitrag zur anatomischen und systematisohen Kenntniss der 

 Actmien, Jenaische Zeitschr., Bd. xix. pp. 430-488, pis. iv. v. 



