LEPRALIA PERTUSA. 305 



Lepralia pertusAj Esper. 



Plate XLIII. figs. 4, 5. 



Cellepora PERTUSA, Esper, Pflanz. Cellep. 149, pi. x. fig. 2. 



EscHARiNA PERTUSA, MUne-Edivcirds, Lamk. An. s. Vert. ed. 2, ii. 232. 



EscHARiNA PERLACEA, id. ibid. ii. 234. 



Cellepora perlacea, W. Thompson, Ann. N. H. x. 20. 



Lepralia pkrtusa, Johnston, B. Zooph. ed. 2, 311, pi. liv. fig. 10: Busk, 



B.M. Cat. ii. 80, pi. Ixxviii. fig. 3 (? figs. 1, 2), pi. Ixxix. 



figs. 1, 2: Heller, Bryoz. d. Adr. Meeres, 35, &c. 

 Escharella PERTUSA, Siniff, Flor. Bryoz. pt. ii. .^5. 



Zooecia large, regularly ovate^ tumid, distinct, separated 

 by raised lines ; surface covered with punctures ; ori- 

 fice suborbicular, contracted below by two lateral den- 

 ticles, the lower margin slightly curved outwards ; 

 usually a tubercle below the mouth, which sometimes 

 rises into a well developed mucro ; peristome slightly 

 thickened, unarmed ; rarely an avicularium on one side, 

 a little below the orifice, with semicircular mandible 

 directed obliquely upwards. Ooecia globose, somewhat 

 depressed in front, thickly covered with punctures of 

 different sizes, and with a smooth border round the 

 base. 



Colonies forming circular patches, the cells radiating 

 from a common centre, of a fine orange colour ; very 

 bright and silvery when fresh. 



Range of Variation. Busk credits this fine species with 

 a large amount of variability ; but I confess I should give 

 it a very different character. As I have found it, it is 

 remarkably constant in all its leading features, and at 

 once recognizable by its large, ovate, and very tumid cell, 

 and its almost circular mouth ^. I have never met with 

 any variety of it at all resembling the form represented 



* The orifice is slightly elongated transversely. 



X 



