94 CCELENTERATA 



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 inanubrium. 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. 



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

 less irregularly over the hydranth. 



&! Tentacles filiform ; no free medusae 1. CLAVIDAE 



6 2 Tentacles knobbed 2. COKYNIDAE 



a 2 Hydranth with a basal whorl and with or without distal tentacles. 

 &! Hydranth with a basal whorl and no distal tentacles. 

 G! Colony arborescent. 



rfj Hypostome conical ; free medusae present 3. BOUGAINVILLIIDAE 



d a Hypostome trumpet-shaped ; sporosacs present 4. EUDENDRIIDAE 



c 2 Colony not arborescent, but incrusting. 



dt Sporosacs present and no free medusae 5. HYDRACTINIIDAE 



d z Medusae present 6. PODOCOEYNIDAE 



6 2 Hydranth with both basal and distal tentacles. 



d Distal tentacles knobbed 7. PENNABIIDAE 



c 2 Distal tentacles filiform ; hydranths of large size. 

 di Free medusae present. 



6j Hydranths solitary 8. CORYMORPHIDAE 



63 Hydranths colonial 9. DENDROCLAVIDAE 



d z Sporosacs in pendant clusters present 10. TUBULARIIDAE 



B. THE MEDUSAE. 



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



Oj No oral tentacles or lobes present. 

 &j Two or 4 marginal tentacles. 



Cj Tentacles well developed 2. CORYNIDAE 



c a Tentacles rudimentary 7. PENNARIIDAE 



6 3 One long marginal tentacle, the others short (except Ectopleura). 



8. CORYMORPHIDAE 

 c 2 Oral tentacles or lobes present. 

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



3. BOUGAINVILLIIDAE 

 & 2 Tentacles not in clusters. 



d Marginal tentacles 2 or 4 PERIGONIMUS 



c 2 Marginal tentacles 4 or 8 6. PODOCORYNIDAE 



c 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. 



