COELENTERATA. 
773 
Tahularidcc and Ca'mpanularid(R. Allman (Ann. & Mag. 
Nat. Hist. 1864, xiii. pp. 345-380), gives a most valuable syn- 
opsis of the genera and species of the Tubularian and Cam- 
panularian Hydroids whose trophosomes are known : — 
The author very justl}^ observes that henceforth no classification of the 
Ilj^droida will be admitted wliicli does not include in the conception of every 
ITydroid both those parts which are destined for the nutrition of the 
colony and those wliich are destined for the sexual perpetuation of the 
species, whether these latter be in the form of fixed sacs or of free locomo- 
tive medusfo. The following technical names are used in this paper : — tro- 
phosorne ” = the assemblage of nutritive zooids : gonosome ” = the assemblage 
of generative zooids ; the gonosome sometimes remains permanently attached 
to the trophosome, sometimes becomes free. “ Gonopliore'''' — repro- 
ductive bodies ; if the gonophores be in the condition of a fixed sac, they 
are called adclocodonic, if in that of a developed medusa, plianerocodonic. 
Sometimes similar gonosomes are associated with dissimilar trophosomes 
(isogonism), sometimes dissimilar gonosomes are associated with similar 
trophosomes (heterogonism), J'he cccnosarc ” is the common comiecting 
basis of the colony, and is more or less completely invested by a chitinous 
periderm ” excreted from its surface. The hydrorhiza ” is the root- 
like proximal termination to the coenosarc. The ^Giydrocaulus'’’ is the free 
or more less adherent portion of the coenosarc which intervenes between the 
hydrorhiza and the polypites. The meiastome ” is that portion of the poly- 
pite which intervenes between the mouth and the most distal set of tenta- 
cles. The hydrotheca ” is the cup-like receptacle into which the polypites 
are retractile in the Campanularian Hydroids. When the gonophore is 
adelocodonic the umbrella is never developed so as to present a wide orifice 
or “ codonostome,’’^ and hence is incapable of locomotion. 
Until very recently the Gymnophthalniata have been described and arranged 
as independent forms, although there was little doubt that many of them 
were onl}’^ the locomotive buds of fixed Hydroids ; henceforward the aim of 
the zoologist will be to investigate the whole life-history of each form, and 
to trace it from the ovum to the full-grown trophosome and gonosome, and 
then to the plianerocodonic gonophore producing the ova in its turn. Out 
of the numerous species and genera the complete life-history of only two or 
three is known, and of very many of the species the gonophores are unknown ; 
these are marked thus (*) in the following Hst of the families, genera, and 
species. The author gives the diagnosis of each genus, but enumerates the 
names of the species only : — 
TUBULARTHtE. 
Fani. I. Clavidje. 
1. Clava (Gm.) : C. imdticornis (Forsk.), C. repens (Wright), C. leptostyla 
(Agass), C. diffusa (Alim.), C. cornea (Wright), C. memhranacea (Wright), 
C. nodosa (Wright). 
2. Tubiclava (Alim.) : T. lucerna (Alim.). 
3. Merona (Norman) : M. cornucopia^ Tuhiclava cornucopia (Norman). 
4. Campaniclava^ g. n. : C. cleodorcc= Syncoryne cleodorce (Gegenb.). 
5. Turn's (Lesson) : 1\ neqlccta (Forbes), TYOTp\iosomo,-= Clavula gossii 
(Wright). 
