108 ALDER, ON NEW BRITISH POLYZOA. 
erect. Another example of this species has lately been 
dredged on the Durham coast, by Mr. G. 8. Brady and Mr. 
Hodge. It appears to be a Mediterranean species, and has 
also been found in Madeira by Mr. J. Y. Johnson. This is 
the first notice of its occurrence on the British coast. 
Order Cyciostomata, Busk. 
Family IpMoneip#, Busk. 
Genus HORNERA, Lamouroux. 
Horner BOREALIS, Busk. (Pl. IV, figs. 1—6.) 
Polyzoary white, much and irregularly branched; the 
branches commencing almost from the base, stout below, 
undulating, and gradually tapering to the extremities ; they 
are cylindrical or a little compressed, curving slightly inwards 
below on the smooth side, and rather bent outwards towards 
their extremities; the cell-apertures are arranged nearly in 
quincunx on the outside of the branches; the central ones 
are orbicular and slightly tubular, with an even rim; those 
towards the sides are more produced, dilated and expanded 
obliquely towards their extremities, and sometimes ending in 
an acute point, but more frequently slightly rounded; there 
are three or four cells in each transverse row. The surface 
on this side is striated in an undulating manner, and there 
are numerous small, sub-tubular perforations (some of which 
appear to be avicularia), somewhat irregularly disposed, but 
generally following the margins of the cells. ‘The inner or 
back part of the branches is smooth, without cells, but with 
faint undulating ridges, and a few very small punctures like 
sunken tubes. The ovicells are placed on this side, generally 
near the junction of a branch, forming yellowish, sub-globu- 
lar protuberances, of a hard, calcareous nature, and appear- 
ing reticulated or coarsely punctured under a magnifier; a 
tubular aperture is seen at one side (Pl. V, fig. 6). Height, 
about three quarters of an inch; lateral expansion about the 
same; thickness of the branches, from ;),th to jth of an 
inch. 
Hornera frondiculata, Busk, in ‘Ann. Nat. Hist.,’ 2nd 
Ser., v. xvili, p. 84, t. 1, fig. 7; Sars (Reise i Lof. og Finm.), - 
“Nyt Mag.,’ v. vi, p. 146. 
Hornera borealis, Busk, ‘ Crag Polyzoa,’ p. 103 (without 
description). 
This interesting Hornera, the first of the genus discovered 
