94 CCELENTEEATA 



medusae or sessile medusoid buds. The medusae (Fig. 147, B) are known 

 as Anthomedusae and are usually more or less bell-shaped and ocellate and 

 bear the gonads on the manubrium. Many of them have never been traced 

 to the hydroids which produce them : about 15 families. 

 Key to the families of Tubulariae here described : 



A. THE HYDROIDS. 



tti Hydranth without a basal whorl of tentacles, these being scattered more or 

 less irregularly over the hydranth. 



6i Tentacles filiform ; no free medusae 1. Clavidae 



62 Tentacles knobbed 2. Corynidae 



Oj Hydranth with a basal whorl and with or without distal tentacles. 

 bi Hydranth with a basal whorl and no distal tentacles. 

 Ci Colony arborescent. 



di Hypostome conical ; free medusae present 3. Bougainvilliidae 



da Hypostome trumpet-shaped; sporosacs present 4. Eudendriidae 



C2 Colony not arborescent, but incrusting. 



di Sporosacs present and no free medusae 5. Hydractiniidae 



dz Medusae present 6. Podocorynidae 



62 Hydranth with both basal and distal tentacles. 



Ci Distal tentacles knobbed 7. Pennaeiidae 



C2 Distal tentacles filiform ; hydranths of large size. 

 di Free medusae present. 



61 Hydranths solitary 8. Corymorphidae 



62 Hydranths colonial 0. Dendroclavidae 



dz Sporosacs in pendant clusters present 10. Tubulariidae 



B. THE MEDUSAE. 



(The 1st, 4th, .5th and 10th families produce no free medusae.) 



Oi No oral tentacles or lobes present. 



61 Two or 4 marginal tentacles. 



Ci Tentacles well developed 2. Corynidae 



C2 Tentacles rudimentary 7. Pennariidae 



6a One long marginal tentacle, the others short (except Ectopleura) . 



8. Corymorphidae 

 Oj Oral tentacles or lobes present. 

 &i Marginal tentacles in 4 or 8 clusters (except Perigonimus) . 



3. Bougainvilliidae 



62 Tentacles not in clusters. 



Ci Marginal tentacles 2 or 4 Perigonimus 



Cj Marginal tentacles 4 or 8 6. Podocorynidae 



C3 Marginal tentacles numerous 9. Dendroclavidae 



Family 1. CLAVIDAE. 



Trophosome : colony either branching or consisting of an extensive, 

 filiform hydrorhiza from which rise the polyps; hydranths elongate and 

 bearing numerous filiform tentacles irregularly placed. Gonosome : gono- 

 phores in clusters either just below the tentacles or on special branches 

 or even rising independently from the hydrorhiza, forming sporosacs and 

 never medusae: about 5 genera. 



