CLASSIFICATION OF ACTINIARIA 547 
AURELIANIDAE. Genera: Aureliania, Actinoporus. 
Common characters, 9. 
1. Definite base. 2. Sphincter strong endodermal circumscribed. 
3. Tentacles have the form of small vesicles, and may be lobed. 
4. More than one tentacle to each main endocoel, 5. More than one 
tentacle to each main exocoel. 6. One siphonoglyphe. 7. All the 
mesenteries, or all the older ones, perfect. 8. Mesenteries either 
all with the grade of macrocnemes (and with unusually strong circum- 
scribed retractors), or else more or less divided into macro- and 
microcnemes. 9. No acontia. 
Here the disc and tentacle radial muscle may be ectodermal or _ 
mesogloeal, and there are vesicular verrucae in one genus. 
PHYMANTHIDAE. Genus: Phymanthus. Main charac- 
ters, 10. 
1. Definite base, sometimes reduced. 2. No vesicles. 3. No 
developed sphincter. 4. Disc and tentacle radial muscle ectodermal 
or with a mesogloeal tendency. 5. Tentacles divided into marginal 
and discal, the former tentaculiform and usually pinnate, the latter 
more usually papilliform (rarely they are absent). 6. Marginal 
tentacles not more than one per exo- and endocoel. 7. Discal tentacles 
typically in radial rows—they may occur on exocoels as well as 
endocoels. 8. Mesenteries not properly divided into macro- and 
microcnemes as a rule, though coming very near it sometimes. 
9. Numerous perfect mesenteries. 10. No acontia. 
ACTINODENDRIDAE. Genera: Actinodendron, Mega- 
lactis, Actinostephanus. Common characters,10. 
1. Definite base. 2. No vesicles. 3. No developed sphincter, 
4, Dise and tentacle radial muscle ectodermal. 5. Disc produced 
into permanent arm-like lobes. 6. Numerous tentacles per endocoel. 
7. Numerous tentacles per exococl. 8. Mesenteries not divided into 
macro- and microcnemes. 9. Numerous perfect mesenteries, 10, No 
acontia. 
HoMOostIcHANTHIDAR. Genus: Homostichanthus. Main 
characters, 11. 
1. Definite base. 2. No vesicles. 3. Sphincter endodermal, not 
strong. 4. Oral dise not formed into arm-like permanent lobes. 
5. Tentacles short and papilla-like, simple. 6. Numerous tentacles 
per endocoel. 7. Numerous tentacles per exocoel. 8. Tentacular 
longitudinal muscle ectodermal. 9. Mesenteries not divided into 
