ON THE SHETLAND CRUSTACEA, TUNICATA, ETC. 311 



Suborder CTENOSTOMATA. 



Alcyonidium gelatinosum (Pallas) . 40-50 fathoms, 5-8 miles east of Balta, 

 sandy bottom, with immense quantities of Hydrozoa and Tunicata ; also 

 40 fathoms, six miles north of Whalsey Lighthouse. 



Mrsutum (Fleming). On Fuci, tide-marks, Balta Sound, and Out Sker- 

 ries, abundant. 



? A third species was found by me in 1861 between tide-marks, "West 



Yoe, Out Skerries. Mr. Alder, who examined it for me, gave me the 

 MS. name for it, " Alcyonidium radiatum" 



Arachnidia Tiippotlwoides, Hincks, Cat. Zoophytes Devon and Cornwall, p. 57, 

 pi. xvi. fig. 2. Creeping over the test of Ascidia sordida; dredged 

 5-8 miles off Balta. 



Flmtrella hispida (Fsibr.^Flustra hispida, Johnst. Brit. Zooph. p. 263, 

 pi. Ixvi. fig. 5, = Flustrella Jiispida, Gray, Brit. Eadiated Anim. Brit. Mus. 

 p. 108 ; Redfern, Quart. Journ. Mic. Sci. N. S. vol. vi. 1858, p. 96, 

 pi. iv., = Alcyonidium hispidum, Smitt, Ofvers. af K. Yet.-Akad. Porh. 

 1866, p. 499, pi. xii. figs. 22-27. On Fuci, Chondrus, and other sea- 

 weeds ; common. 



Vesicularia spinosa (Linn.). Shetland, 1858, Barlee " (fide Alder in litt.). 



BusJcia nitens, Alder, Cat. Zooph. Northumb. and Durham, p. 66, pi. v. 

 figs. 1, 2 ; Quart. Journ. Mic. Sci. N. S, vol. v. 1857, p. 24, pi. xiii. 

 figs. 1,2. " On Haledum labrosum, procured by Mr. Barlee " (Alder 

 in litt.). 

 Vallceria cuscuta (Linn.). Procured in 1861. 



J3oiverbanJcia imbricata (Adams). Tide-marks, common. 



Avenella fusca, Dalyell, Rare and Rem. Anim. Scot. vol. ii. p. 65; vol. i. 

 pi. xii. fig. 11 ; Alder, Cat. Zooph. Northumb. and Durham, p. 69, = 

 Farrella fusca, Busk, Quart. Journ. Mic. Sci. vol. vi. fig. 3, =Farrella 

 dilatata, Hincks, Quart. Journ. Mic. Sci. vol. viii. p. 279, pi. xxx. fig. 7 ; 

 Cat. Zooph. Devon and Cornwall, p. 30. Parasitic on the tests of 

 Ascidians from deep water. 



Suborder PEDICELLINEA. 



Pedicellina Belgica, Van Ben. Recognized by Mr. Alder on some Shetland 

 Hydrozoa sent to him in 1861. 



gracilis, Sars. On Sertularia, 1863 ; rare. 



. ecliinata, Sars. " In Dourie Yoe, 15 fathoms, 1864 " (fide Peach). 



Suborder LOPHOPEA. 



I have pleasure in announcing the discovery in the Shetland seas of a 

 species of this interesting tribe, which up to the present time has been 

 supposed to embrace only freshwater forms. Rliabdopleura was dredged by 

 me in the Outer Haaf, and being unable to recognize it, I sent it to Pro- 

 fessor Allman for his opinion, and the extract from a letter received from 

 him, given below, will show the result of his examination. 



Rliabdopleura Normani, Allman, nov. gen. et sp. " Now with regard to the 

 new genus. Expecting nothing but hydroids in your bottles, and being 

 satisfied on a rapid glance that the contents of one bottle were some- 

 thing very different from any known hydroid, I at once set the specimen 

 down in my mind as that of a new genus of Campanularians. I now 

 find that it is no hydroid, but a very curious and new genus of Polyzoa. 

 So interesting a form is it that I thought it worth while spending some 



