20 Mr. R. Kirkpr.trick on 



it does not possess the feature characteristic of that genus, 

 viz. a mucro. The process present on the proximal border of 

 the orifice is a prolongation of the front wall of the zocecium, 

 which fits into a concavity in the operculum. The operculum 

 possesses a peculiar framework. The ovicells are of immense 

 size in comparison with the zooecia, and the orifices and 

 opercula of fertile zooecia are enlarged and modified. 

 Hab. Tizard Reef, 27 fath. 



Lepralia onucha, n. sp. (PI. V. figs. 5, 5 a.) 



Zoarium incrusting. Zooecia dull brown, *8 mm. long by 

 •5 broad ; surface flattened, rising at the oral end ; walls 

 thick, opaque, smooth, glistening ; orifice rectangular, '2 mm. 

 in length by *14 mm. in breadth, with slightly concave lower 

 border, surrounded at the sides and back by a low peristome. 

 Avicularia 0. Ocecium forming an ill-defined swelling at the 

 back of the peristome. 



Operculum rectangular, *2 mm. in length by '14 mm. in 

 breadth ; with a thick rim surrounding the proximal half, 

 with knobs for muscle attachment ; giving off from about the 

 middle of the upper surface a chitinous claw, which fits 

 posteriorly into a groove in the peristome. 



Hab. Incrusting coral ; Macclesfield, 36 fath. 



Phylactella geometrica, n. sp. (PI. V. figs. 7-7 c.) 



Zoarium incrusting. Zooecia ovate-elongate, slightly ven- 

 tricose ; front wall smooth, hyaline, bounded by an areolated 

 margin ; zooecia rising anteriorly to a tall cylindrical peri- 

 stome ; primary orifice quadrangular, with three denticles ; 

 by the side of the peristome a shallow rudimentary avi- 

 cularium (in many cases aborted or absent), with broad 

 pyriform mandible. 



Ooecium globose, punctured, hyaline. 



Hab. Incrusting coral ; Tizard Reef, 35 fath. 



Mucronella Thenardii, Audouin. (PL IV. figs. 2-2 b.) 



Flustra Thenardii, Audouin ; Savigny, Descr. de l'Egypte, pi. x. 

 figs. 3, 3 a. 



Zoarium incrusting. Zooecia large, ventricose, with thick 

 glassy walls, perforated by large round pores ; from the middle 

 of the lower border of the orifice a stout tridentate or cross- 

 shaped process arises. 



Orifice quadrate, with a central hammer-shaped and two 



