6o 



Arachnoidea protecta ; and this is specially obvious in an intermediate state of development. 

 When the zooecia have reached their highest development they are hardly distinguishable from 

 a typical Nolella. In the yoting condition the zooecium may be Paludicella-Wke. 



Group C. Vesicularina Johnston. 



Vesicularina (pars), Johnston, 1847, "Hist. Brit. Zooph.", Ed. 2, p. 367. 



Vesicularina Waters, 1910, "Rep. Mar. Biol. Sud. Red Sea", "Bry. II", J. Linn. Soc, Zool., 

 XXXI, p. 240. 



The genera included by Johnston in the Vesicularina were Serialaria {Amathia), Vesiai- 

 laria, Beania, Valkeria, Bowerbankia and Farrella. Of these Beania is now placed among 

 the Cheilostomata, while Valkeria and Farrella have been transferred by Waters to the next 

 division of the Ctenostomata. With these removals the Group remains almost identical with 

 Waters's use of the name. 



The Vesicularina may be defined as consisting of those Ctenostomes in which there is 

 a relatively thick, branching, tubular axis, to which the zooecia 'are directly attached, by a 

 contracted, or an expanded base. The axis is usually divided by diaphragms into internodes, 

 each of which gives off a number of zooecia. Budding only from the axis. The number of 

 tentacles is commonly 8 — 10. Gizzard present in most of the genera, and perhaps in all. 



Family Vesiculariidae Johnston. 



Vesiculariadae (pars), Johnston, 1838, "Hist. Brit. Zooph.", Ed. I, p. 247. 

 Vesiculariadae (pars), Johnston, 1S47, Do, Ed. 2, p. 367. 



Vesiculariadae (pars), Gray, 1848, "List. Brit. An. Brit. Mus.", I, pp. 94, 145. 

 Vesiculariidae Hincks, 1SS0, "Hist. Brit. Mar. Pol.", p. 512. 



The Family, as originally introduced by Johnston, included Vesicularia, Serialaria, 

 Valkeria and Bozoeröatikia. In the second Edition of his work the list of genera is identical with 

 that given above for the Vesicularina. Hincks included Avcnclla in it; — an association on 

 which I am not able to express a positive opinion. Zoobotryon doubtless belongs to this family. 



As defined by Hincks, the Family consists of Ctenostomes having "Zooecia contracted 

 "below, not closely united to the stem at the base, deciduous, destitute of a membranous area. 

 Zoarium repent or erect". Part of this definition must certainly be excluded, since the zooecia 

 in Amathia are not contracted proximally nor individually deciduous. The definition of the 

 Family may provisionally be given as identical with that of the Vesicularina, since it is at 

 present uncertain whether any of the genera referable to the group deserve separate Family 

 rank. Farrella, which may belong to this Family, is believed to have no gizzard, a structure 

 which is known to occur in most of the other genera. 



In the group Paludicellea the appearance of a "stolon", in certain genera, is due to the 

 fact that the proximal ends of the zooecia are much narrower than the expanded distal ends. 

 In the Vesiculariidae nothine of the kind occurs. The axis is sharply marked off from the 



