MEMBRANIPORA MONOSTACHYS. 131 



triangular structures, wliich bear a general resemblance 

 to the pointed form of avicularium. 



Habitat. On stones and shells from tide-marks to 

 deep water. 



Localities. Cornwall, in Falmouth and Fowey rivers, 

 on mussel- and oyster-shells ; oflF the Deadman (Couch) : 

 South Devon, between tide-marks and from moderate 

 depths, common; Ramsay, Isle of Man, on stones in 

 tide-pools (T. H.) : on stones east of Kingstown Harbour 

 (Hassall) : St. Andrews, on a valve of Cyprina Islandica 

 from deep water (Dr. M'^Intosh) : Tynemouth, a single 

 specimen (Alder) : Hastings, common (Miss Jelly). 



Geographical Distribution. Mediterranean (Savigny) : 

 coast of Florida, 13-60 fathoms (Pom-tales) : St. Lawrence 

 (Whiteaves) *. 



Range in Time. Coralline and Red Crag (part.) 

 (Middle Pliocene) ; Palaeolithic (A. Bell) : Austro-Hun- 

 garian Miocene and Pliocene deposits ; Vienna Basin 

 (Reuss) : Italian Pliocene beds at Volterra (Manzoni) : 

 Postpliocene (Dawson) . 



MeMBRANIPORA MONOSTACHYS, Busk. 

 Plate XVII. figs. 3, 4 ; Plate XVIII. figs. 1-4. 



Membranipora MONOSTACHYS, Busk, B.M. Cat. ii. 61, pi. Ixx. ; Crag Pol. 



31, pi. ii. fig. 2: Hincks, Devon. Cat. 38 (sep.), Ann. N. 



H. ser. 3, ix. 28. 

 Flustra distans, Landsb. Pop. Hist. B. Z. 354 (not F. distans, HassaU). 

 Membranipora pilosa, 4, forma monostachys, Smitt, CEfvers. K. Vet.-Ak. 



Forh. 1867, 370 and 416. 

 ?FriUSTRELLARiA PUSTULOSA, U Orb. Pal. Fran9. Terr. Oret. v. 526, pi. dccxxr. 



figs. 22-25. 

 ? Membranipora nobilis, Beuss, Foss. Polyp. W. Tertiarb. 98, pi. xi. fig. 26. 



* The M. Lacroixii of Packard's List of Labrador Inyertebrata is refer- 

 able, according to Smitt (who had seen a specimen forwarded by the above 

 natiu-alist), to his M. Americana. 



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