74 DUBLIN UNIVERSITY 



Sub-Order. — Cyclostomata. 

 Alecto 



incurvata, n. sp. (Hincks). Antrim, on stones from deep water. 

 B. D. R. 1858, List of Polyzoa (Hincks), where it is recorded as 

 a Tubulipora. 



Sub- Order. — Ctenostomata. 

 Farrella 



dilatata, n. sp. (Hincks). [Avenella dilatata (mihi). B. D. Kep. 



for 1858.] Antrim, on shejl. 



Order.— HIPPOCEEPIA. 



Lophopus 



crystallinus. Pond in Zoological Gardens, Dublin. Allman, Mono- 

 graph on the Fresh- water Polyzoa, 1856. 

 Plumatella 



elegans (Allman). Mill-pond, Bandon, county of Cork. Allman, 

 Monograph, &c. 



Descriptions of JVew Poly%oa. 



Fam MEMBR ANIPORlDiE. 



Genus, Membranipora. 

 I. Membranipora imbellis, n. sp. (Hincks). Plate III., Fig. 1. 



Cells ovate, distinct, broad below, with a membranous covering, no cal- 

 careous expansion; margin raised, much thickened, and beaded; ovicell 

 very prominent, frosted, with a rib or raised edging round the front ; no 

 spines or avicularia. 



The examination of a large number of specimens from various locali- 

 ties, exhibiting a striking uniformity of character, has convinced me 

 that this form should be accounted a species, and that it is not a mere 

 variety of M. Flemingii. The cells are larger, less crowded, and more 

 distinct than in the last-named species, and the covering is altogether 

 membranous ; the rim is raised, and adorned with a beading, the inner 

 edge slightly crenulate ; the lower margin is wider than the rest ; the 

 ovicell is prominent, with a rib, or raised line, which forms a border 

 round the front of it ; the enclosed area is frosted. I have never de- 

 tected, even in the youngest and freshest specimens, any trace of spines 

 or avicularia. The polyzoary is generally dull and opaque, and coarse 



