240 MARINE BIOLOGY OF THE SUDANESE RED SEA. 
give off numerous radicles, but a consideration of his list, in the ‘ Challenger ’ 
Report, suggests that they are not closely allied. 
The larva of but few genera is known, but Prouho shows that Hypophorella 
lays an egg, and has a larva with the characters of Cyphonautes, though 
whether it has a “shell” is not conclusively shown. Several of the Cteno- 
stomata discharge an unsegmented egg, either through an intertentacular 
organ (Alcyonidium duplex, Prouho ; A. albidum, Ald.) or through a simple 
opening by the base of the tentacles (as in Hypophorella, Ehlers ; Farella 
repens, Farre), butin the majority the larva develops in the tentacular sheath. 
This naturally requires much space, and the polypide usually dies down as 
the larva develops. In the Cheilostomata, when there is an ordinary ovicell, 
whether external or internal (as in Lepralia cucullata, &e.), there is no 
necessity for the disappearance of the polypide, and we find long rows of 
polypides in perfect activity, with ova developing and larvee in the ovicells. 
Exact observations on the development have been made on but few Cteno- 
stomata. It is very likely that a comparative study of the primary zocecia of 
the Ctenostomata may give us valuable assistance. 
Pending further examination the Ctenostomata may be provisionally 
tabulated as 
ALCYONELLEA. 
Usually many tentacles ; no gizzard ; larva in some species with intestine, 
and sometimes Cyphonautes. 
Alcyonidium, Lamx. 15-27 tentacles ; no gizzard. 
Flustrella, Gray. 19-27 tentacles (Waters), 30-35 (fincks); no 
gizzard. 
Pherusa, Lamx. 15 tentacles (Waters) ; no gizzard. 
Lobiancopora, Pergens*. 24 tentacles ; no gizzard. Probably belongs 
here. 
? Clavopora, Busk, 1874. Apparently belongs to this division. It has 
been subsequently described as Aschoriza, Fewkes (16-18 tentacles) 
(Robertson). 
VESICULARINA. 
Usually 8-10 tentacles ; a gizzard; the zocecia grow direct from the stem 
and have no independent movement. 
Zoobotryon, Ehr. 8 tentacles ; a gizzard. 
Bowerbankia, Farre. 8-10 tentacles; a gizzard. Apparently a syno- 
nym of Zoohotryon. 
Amathia, Lamx. 8-10 tentacles ; a gizzard. 
Vesicularia, Thomps. 8 tentacles; a gizzard. 
? Avenella, Dalzell. 20-24 tentacles ; a gizzard (Hineks). 
* Sections show that Lobiancopora hyalina, Pergens, has an intertentacular organ. 
