524 ME. G. C. BOUENB ON THE GENUS LEMNALIA AND 



the other by a network of tubular solenia, we have a fairly good idea of the composition 

 of the Alcyonid anthodete. It must be borne in mind, however, that the anthosteles 

 corresponding to the secondary axes of a corymb do not open directly into the cavity of 

 the primary axis, but into solenia grooving out from it. The same is the case with the 

 tertiary and other axes which open into tbe secondary axes, through the intervention 

 of solenia. 



In the Alcyonid(B the colonies are comparatively simple in shape — mushroom-shaped, 

 as in Saroophyton ; lobate or bluntly digitate, as in Alcyonium ; none of them branch to 

 any great extent. In forms like Sarcophytou the apodete is confined to the distal 

 svu-face of the anthodete, the latter being swollen in this region to form the"pileus," 

 while the syndete forms a stem. But in Alcyonium and its allies the apodete occupies 

 nearly the whole surface of the anthodete, being absent only over a very restricted area 

 at its basal end. This is the result of the mode of aggregation and budding of the 

 zooids, the anthocoditc standing out all over the surface of the anthodete. In the 

 Nephtliyidce, on the other hand, the anthodete is variously ramified, and the anthocodiye 

 emerge only on the terminal branches and twigs, where they form clusters. Thus the 

 syndete may be described as forming a barren stem and In-anches composed of the adnate 

 anthosteles of a certain number of tlu^ zooids forming the colony ; the apodete is 

 confined to the terminal twigs. Wright and Studer * have described the zooid-cavities, 

 i. e. the anthosteles, of the Ncplithi/hhc as narrowing below, and ending each in a cnl-de- 

 snc, but comnmnicating by means of solenia with wide canals, which run in the stem 

 and larger branches ; these wide canals they called stem-canals or branch-canals. But 

 KoUiker f long since pointed out that in Siphonogonjia Godeffroyi the stem-canals contain 

 prolongations of the mesenteries of the zooids, and are, in fact, the extremely long 

 anthosteles of the primary zooids of tlie colony ; and the case is not different in other 

 members oi\X\Q jSepldhyidce. I have examined different species of ^mwo/Zjew, Sponyodes, 

 Lemnalia, and Sipho)togorgia, and find that in each the so-called stem-canals are 

 nothing more than the extremely long anthosteles of the primary zooids, and contain 

 prolongations of the asulcar mesenteries, sometimes also of the remaining six mesen- 

 teries. It is true that most of the anthosteles in a Nephthyid colony do thin out and end 

 blindlv as described by Wright and Studer, but these belong to the secondary, tertiary, 

 and other zooids which spring from the solenia given off by the primary zooids. The 

 continitity of a stem-canal with a zooid-cavity can be determined only by the patient 

 study of long series of sections. 



Perhaps the difference betAveen the Alcyonidce and the Nephthyidce may be best 

 understood if the anthodete of the latter is regarded as a bundle, not of corymbs, but of 

 compound racemes whose main axes are of very various lengths. Let us imagine a 

 number of racemes a, h, c, d (tig. 3), whose secondary and tertiary axes are long, 

 parallel to and fused with the priuiary axis. The proximal parts of all the racemes are 



* ' Challenger ' Ecports, Zoology, vol. xssi., Alcyonaria, 1889. 



t A. von Kiillikcr, ' Festschrift zur Feier des ;i.5-jahrigen Bestehens d. phys.-med. GeseUschaft in Wiirzburg,' 

 1874, p. 18. 



