BEITISH PAL^OGBNE BfiYOZOA. 249 



Species 2. Umbonula calcaeiformisI, n. sp. 



Diagnosis. Zoarium, a thick encrusting mass. 



Zocecia roughly hexagonal in shape : short and thick. The front wall granular. 

 The aperture is suborbicular, somewhat irregular on the lower margin from the 

 ingrowth of the avicularia. The front wall is very tumid, and bears a large avicularian 

 cell, this is attached to the front wall and continues over it as a pair of sharp pointed 

 processes. The pore of the avicularium is raised and close beside the zooecial aperture. 

 The avicularium is always lateral and oblique. 



Ooecia globose, low, and comparatively small. 



Distribution. London Clay, Fareham. 



Type. Brit. Mus. No. B 3831. (Growing on Hornera.) 



Figure. PI. XXXT. fig. 3. X 55 diam. 



Affinities. The shape of the aperture, the tumid front wall, and the umbonate avicu- 

 larium all agree with the genus Umbonula. Amongst the other species it probably is 

 most nearly allied to U. bartonense, Greg., but from this it may be distinguished by its 

 suborbicular aperture, the lateral position of the avicularia, and the pores of these 

 being terminal instead of in the angle overhung by the umbo. 



Subfamily Teichoporin^. 

 Genus Teichopoka^, n. g. 



Diagnosis. Zoarium foliaceous or encrusting : in large flat surfaces. 



Zocecia pyriform, much expanded above ; elongate. Aperture large, holostomatous, 

 orbicular ; surrounded by a raised ring. Usually long sinuous lines of marginal areolae 

 continuous across successive zooecia. 



Goncecia with the aperture contracted either marginally or by a bar or a central 

 spot. 



Species 1. Teichopoea cajAVATA. 



Diagnosis. Zoarium in large foliaceous expansions. 



Zocecia clavate, the lower part being much restricted in width. Orifice very large ; 

 the surrounding ring is continuous with the ridge on the front wall of the zooecia. 

 Punctures large and numerous. 



Avicularia : usually one, just below the orifice; lateral. 



' From the spur-shape of the avicularian cell. 

 " From re'ixos, the waU of a fortress. 



