some British Polyzoa. 209 



iriTgnlar margin, but would appear to liave a lip-like 

 projection (fig. 7). 



The calcareous shells of the Annelidan genus Diirupa are 

 dredged in extraordinary profusion on some parts of the 

 " Haaf " off Shetland. I had saved a large box full of 

 specimens of these, selected on account of encrusting growths 

 on them, mostly of Polyzoa. On examining the contents of 

 this box, which contained at least two thousand Ditrupce, I 

 discovered in one specimen the Terehripora which I have 

 here described. 



ScMzoporella Alderi (Busk). 



This species is subject to some variation in its mode of 

 growth and in the absence or presence of lateral avicularia. 

 It has been several times described. The original illustra- 

 tions of Busk are very good. The following will give the 

 synonymy of the species : — 



Var. a. — Chain-like growth ; without avicularia. 



1856. Alysidota Alderi, Busk, Quart. Journ. Micr. Sci. vol. iv. p. 31], 



pi. ix. tigs. 6, 7. 

 1869. Alysidota Alderi, Norman, " Last Report Dredging Shetland," 



Brit. Assoc. Rep. for 1868, p. 306. 



Var. b. — Chain-like growth ; with avicularia. (Chiefly 

 arctic^ rare Shetland.) 



1867. Mollia vulgaris, forma ansata (partim), Smitt, "Kritisk Forteck. 



&c.," CEfvers. K. Vet.-Akad. Forhand. p. 15, pi. xxv. fig. 81. 

 1880. Schizoporella Alderi, Hincks, Hist. Brit. Marine Poljzoa, p. 243, 



pi. xxxvi. figs. 9, 9 a. 



Var. c. — Clustered growth; without avicularia. (Shetland, 

 &c.) 



1860. Lepralia Barleei, Busk, Quart. Journ. Micr. Sci. vol. vii. p. 143, 



pi. xxvi. figs. 1, 2. 

 1867. Mollia vulgaris, forma ansata (partim), Smitt, L c. figs. 79, 82. 

 1880. Schizoporella Alderi, Hincks, /. c. fig. 10. 



Var. d. — Clustered growth ; with avicularia. (Arctic.) 



1867. Mollia vulgaris, var. ansata (partim), Smitt, I. c. fig. 80. 

 1900. Schizoporella Elmwoodicp, Waters, " Bryozoa from Franz Josef 

 Land," Journ. Linn. Soc, Zool. vol. xxviii. p. 66, pi. ix. figs. 1 & 13. 



1905. Schizoporella Storyni, Nordgaard, Ilydrog. and Biol. Invest., 

 Invert. Norweg. Fiords, p. 166, pi. v. figs. ], 2. 



1906. Schizoporella Ebnwoodice, Khige, Ergauz. u. die 'Olga' Exped. 

 gesamm. Bryozoen, p. 40. 



1906. Sc/ii-o^wYZ/rt .S'/ora;/, Nordgaard, T^rvozoa from Second 'Fram' 

 Exped. 1898 1902, p. 17, pi. i. figs. 10, 11. 



