Rev. T. Hincks on British Polyzoa.' 529 



with his suggestion, and to avoid confusion, I have assigned 

 this name to L. monodon. 



Many other distinct groups are blended in the genus 

 Leprcdia of authors ; I merely give the foregoing as a sample 

 of the work of redistribution which has to be done, and must 

 reserve the more complete treatment of the subject for some 

 future opportunity. 



The genus Memhrani-pora also includes a large number of 

 species ; but there seem to be few distinct types of structure 

 amongst them. 



1. MiCEOPORA, Gray. 



{Memhranipora, part, Busk. 

 Lepralia, part, Norman, &c.) 



Zoarium incrusting ; zoocacia with prominent raised mar- 

 gins ; front depressed, wholly calcareous ; oral aperture semi- 

 circular, enclosed by a calcareous border. 



Brit. spec. Memhranipora coriacea^ Esper. 

 Lepralia complanata^ N-orman. 



2. Setosella, nov. gen. 



(^Memhranipora, part, Busk. 

 Ctqndaria, part, Smitt.) 



Zoarium incrusting ; zoocecia with raised margins ; front 

 depressed and wholly calcareous ; aperture semicircular ; 

 vibractdar cells alternating with the zoooecia throughout the 

 colony ; vihracula setiform. 



Type Memhranipora vulnerata. Busk. 



3. Megapoea, nov. gen. 

 (Lepralia, part, Busk.) 



Zoarium incrusting; zoooecia with prominent raised mar- 

 gins ; front depressed, wholly calcareous ; oral aperture tri- 

 foliate ; oral valve composed of two portions, a fixed trans- 

 versely elongate lamina and a movable lip. 

 - Type Lepralia ringens^ Busk. 



Suborder Ctenostomata, Busk. 



Smitt has pointed out that the principal character on which 

 this suborder is founded, the operculum of setce^ occurs occa- 

 sionally amongst the Cheilostoniata and is not absolutely 

 distinctive. Ehlers questions the validity of this division, 

 and proposes to dismember it, by separating the fleshy forms, 

 Halcyonellea, Ehrenb. {Alcyonidium, &c.), from the Vesicu- 

 lariidce. The latter he would constitute a distinct group, 



Ann. & Mag. N. Hist. Ser. 4. Vol. xx. 36 



