248 ME. J. W. GBEGOET ON THE 



granular. Zocecia separated by deep depressions. A line of areolae around the margin; 

 these vary with the size of the zocecia from 10 to 15 or 18. 



Avicularia : usually one ; lateral, placed close beside the orifice. 



Distribution. Bracklesham Beds, Bracklesham Bay. 



Ti/pe. Brit. Mus. No. 497.34, Edwards Coll. (Encrusting.) 



Figure. PI. XXXI. fig. 2. x 55 diam. 



Affinities. The shape of the orifice shows that this species is a true Lepralia, using 

 that term, of course, in its modern restricted sense. It was figured by Lonsdale as 

 Eschara brongniarti, a mistake due to his having failed to separate it from the 

 Bryozoan on which it is encrusting. A comparison of his figure 9* with his figure 9 

 shows that he has included two diff'erent forms under one name. 



Among the species of Lepralia it most resembles Lepralia angiostoma, Eeuss [No. 1 1, 

 pp. 291, 292, pi. XXX. fig. 3], but it may be distinguished by the smallness of the orifice 

 in the Austrian species. 



Genus Umbonula, Hincks. 

 Diagnosis. Hincks, No. 2, pp. 316 and cxxxviii. 



Species 1. Umbonula baetonense, n. sp. 



Diagnosis. Zoarium adnate, encrusting ; forming a large and fairly thick crust over 

 shells. 



Zocecia very crowded : quincuncially arranged ; small, pyriform. Peristomial 

 aperture semicircular or slightly clithridiate ; lower margin straight ; very large, some- 

 times occupying more than half the front of the zocecium. The front wall is occupied 

 by a large umbo, formed on an avicularian cell, the opening of which is just below the 

 aperture and is hidden by the prominence of the umbo. Around the margin of the 

 zocecium runs a line of areolae ; those of the lower half are large, and from them furrows 

 run some way up towards the umbo ; the areolae are small around the aperture. 



Avicularia and external marsupia none. 



Distribution. Barton Beds, Barton. 



Type. Brit. Mus. No. 49741. 



Figure. PI. XXXI. fig. 4. Portion of zoarium, x 55. diam. 



Gottardi's Eschara prominens [No. i, pp. 306, 307, pi. xiv. fig. 4] probably belongs 

 to this genus, but the species is so diagrammatically figured that I cannot be quite sure. 

 The genus is a convenient one, though, as Mr. Waters has pointed out, it is a very 

 close ally oi Lepralia, and perhaps ought not to be separated from it. The aperture in 

 this species is typically lepralian. 



