264 MYRIOZOIDJ^. 



SCHIZOPORELLA UMBONATA, Busk. 



Plate XXIV. fig. 2. 



LErRAHA UMBONATA, Bus^; Quart. Journ. Mior. Sc. viii. 143, pi. xxvii. 

 fig. 1. 



Zooecia oblongs serial, separated by a narrow raised line, 

 areolated round the margin, and sometimes punctured 

 in front, with a central umbo ; orifice suborbicular or 

 sometimes contracted below, peristome simple, armed 

 with four spines above ; immediately below the orifice 

 a prominent avicularium, with a semicircular mandible. 

 Ocecia large, rounded, umbonate, with a small vitta or 

 depressed area placed obliquely on each side below. 



Habitat. On stone. 



Locality. Shetland (Barlee), 



Mr. Busk compares this form with Lepralia verrucosa. 

 Of its affinities I can only speak doubtfully, as it is one 

 of the few species which I have not had the opportunity 

 of examining ; but in general character it certainly ap- 

 proaches very nearly to S. auriculata ; and as it is stated 

 that the orifice is sometimes contracted below, we may, I 

 think, infer that its closest relationship is with the present 

 group. The umbo in the centre of the cell, and the vittae 

 on the ocecium are the most characteristic features. In 

 most other respects, in the shape and disposition of the 

 cells, in the general form of the orifice, in the number of 

 the spines and the position of the avicularia, it agrees 

 with the preceding species. 



The umbo on the ovicell, as Mr. Busk has remarked, 

 " is merely that belonging to the cell in front of which 

 the ovicell rises. '^ 



