30 THE ANTHOZOA 



and from their walls lateral zooids are given ofl'. (Jeiiera — Telesto, 

 Lamouroux. The colony is low and only slightly ramified. Spicules 

 in the form of broad dentate discs or ramified and irregular. Canjoa, 

 F. Midler. The colonies form tall rami tied masses. The axial zooids 

 large, lateral zooids minute. Spicules rod-like with few sjjines cemented 

 together by a horny substance. [Telesto is usually placed among the 

 Cornulariidae, which it resembles in many respects, in the ramifying or 

 membranaceous stolon, and in the manner in which isolated zooids arise 

 from the stolon. But it ditters from them in the manner of budding 

 from axial zooids. The same character removes it from the Stolonifera, 

 as defined above, though the presence of a stolon suggests its inclusion in 

 that group. It must in any case be regarded as a link between the 

 Stolonifera, especially the Cornulariidae, and the next family.] F.\mtly 

 2. CoELOGORGiDAE. The colony arborescent, attached by stolon -like 

 processes. The stem formed by an axial zooid, with thickened coenen- 

 chymatous walls. Branches formed by axial zooids of the second order, 

 and branchlets by axial zooids of the third order, borne either on two 

 sides or in spirals by the main stem. Spicules straight or curved, 

 bearing lateral processes. Genus — Coelogorgia, M. Edwards. 



Section 2. Pennatulacea. Charadtrs — The colony consists of more 

 or less numerous lateral zooids borne by a much elongated axial zooid. 

 The colony is free (except in Gondul), and the axial zooid forms a scapus 

 or stem, which is again subdivided into a proximal calamus or peduncle, 

 sunk into the sand or mud and destitute of zooids, and a distal rachis 

 which bears two kinds of zooids — autozooids and siphonozooids. Thus 

 the colonies are always dimorphic. Early in development the cavity of 

 the axial zooid is divided into two by a longitudinal partition. The 

 majority of the Pennatulacea have an axis which is composed of a 

 calcified horny substance and is generally described as having a willowy 

 texture. When it is present it runs along the middle of the septum 

 dividing the cavity of the axial zooid, and two additional stem canals are 

 formed as cavities in the septal tissue on either side of the axis, making 

 four stem canals in all. The mesogloea of the stem is much thickened 

 and is penetrated by numerous solenia which communicate on the one 

 hand with the stem canals, on the other hand with the coelentera of 

 the autozooids and siphonozooids borne on the rachis. The endodermic 

 musculature is largely developed, especially in the stem where it forms, 

 in the higher members of tlie group, an external longitudinal and an 

 inner circular layer. 



The higher members of tlu- Pennatulacea have a distinct bilateral 

 symmetry, due to the zooids being borne like the barbs of a feather on 

 two sides of the rachis only, leaving a sterile band on the two remaining 

 sides. Hence four .'surfaces may be distinguished, named I'V KiiUiker 

 the dorsal and ventral sterile surfaces, and the two lateral zooid-bearing 

 surfaces. The names dorsal and ventral are in themselves objectionable, 

 anil KiJlliker's aj)pIication of them was unfortunate, for Jungersen (48) 

 has shown that the so-called ventral side of the Pennatulid colony is, in 

 fact, the asulcar, or as it is frequently called, the dorsal aspect of the 

 terminal zooid. It is evident that the arbitrary use of the terms dorsal 



