234 MR. GL BUSK ON THE POLTZOA 



Fain. 3. Membraniporid^:. 



Genus Membranipora, Blainv. 



1. Membranipora unicornis, Alder. 



Membranipora unicornis, Alder, Cat. Zooph. North, fy Durham, p. 56, 

 pi. viii. fig. 6. 



Membranipora lineata {forma unicornis, /3/3. stadium longius adultum), 

 Smitt, I. c. pp. 365-399, pi. xx. figs. 30, 31. 



? Reptoflustrella americana, D'Orbig. 



Sab. Lat. 82° 27' K (S. W. F.) ; Hamilton's Inlet, Labrador, 

 15 fms. (WallichX) ; Spitzbergen 6-50 fras. ; boreal and arctic 

 seas generally (Smitt) ; coasts of Northumberland and Durham 

 (Alder). 



Fam. 4. Fltjstridji. 

 G-enus Flustra, B. M. Cat. 



1. Flustra serrulata, n. sp. PI. XIII. figs. 2, 3, 4. 



Zoarium constituted of narrow, ligulate, bifurcated branches, 

 slightly expanded at the ends ; zocecia ovoid or oblong, open in 

 front, except quite at the bottom, where there is a very narrow 

 calcareous expansion; border of aperture finely serrated or 

 beaded ;" ocecia small, immersed. 



Hah. Franklin-Pierce Bay, 13 fms. (H. W. F). 



This Flustra appears to be quite a distinct form. The growth 

 is irregularly branched, the branches or lobes varying in width 

 from one eighth to nearly one fourth of an inch, and they are usu- 

 ally forked and slightly expanded at the ends. The substance of 

 the zoarium is thick, and as it shrinks much in drying it is neces- 

 sary, in order to see the characters clearly, to expand it by boil- 

 ing in water, unless the specimen has been preserved in alcohol. 

 The peculiar finely serrulated or beaded border of the aperture 

 is a very distinctive character. 



Fam. 5. Eschabidji. 

 Grenus Myriozottm, Donati. 



1. Mtriozoum coarctatum, Sars (sp.). 



Cellepora coarctata, Sars, Reise Lqf. og Finm. p. 28. 



Leieschara (and Leiescharia) coarctata, id, N. Norsk. Polyz. p. 1^. 



