312 REPORT 1868. 



time over its thorough investigation . . . ; and so by the help of acetic 

 and chromic acids and liquor potassse, I have succeeded in very fairly 

 unravelling the structure of your Polyzoon. It is a true Hippocrepian 

 form, as entirely and typically so as Plumatella a fact which gave 

 facility to my examination, as I had already made the Hippocrepian 

 Polyzoa a special subject of study. One of its most remarkable fea- 

 tures is a rigid rod which runs through the ccenoecium, and to which 

 the polypides are attached, each by a funiculus. This rod was the only 

 thing at first visible besides the polypides and their tubes of insertion ; 

 but I afterwards found that the whole of the rod and its attached 

 polypides were contained in a most delicate and colourless ccenoccium, 

 into which the free tubes of insertion were continued. The remarkable 

 internal rod will well suggest a generic name, and I have accordingly 

 thought of Wiabdopleura as sufficiently significant and distinctive." 

 Allman in litt. Outer Haaf oif Unst, in 93 fathoms. 



Class ECHINODEKMATA. 



The Crinoidea, Ophiuroidea, and Aster videa in the following notes arc 

 arranged in accordance with my paper " On the Genera and Species of British 

 Echinodermata " in the ' Annals of Nat. Hist.' for February 1865. With 

 respect to the Echinoidea and Holothuroidea, I give references where the 

 nomenclature of Porbes's ( British Starfishes ' is not sufficient to indicate the 

 species. 



Order CBINOIDEA. 



Antedon rosaceus (Linck). In the Yoes and thence down to 40 fathoms, 

 not uncommon, and attaining an unusually large size. Yery abundant 

 on Laminaria3, in Bressay Sound, off Lerwick. 



Sarsii (Diiben & Koren). 80-100 fathoms, 40 miles east of Whalsey 



Lighthouse ; very local, but gregarious where found. 



Order OPHIIJEOIDEA. 



Astrophyton Linckii, Milll. & Trosch=^4. scutatum, Porbes. Off the west 

 coast, in very deep water (vide Porbes, British Starfishes). It has not 

 been procured during the recent dredgings off the east and north coasts, 

 nor do the fishermen on those sides of the island appear to be acquainted 

 with the species. 



Ophiothrix fragilis (Miiller) = Ophiocoma rosula and minuta, Porbes. Having 

 a very great range in depth, living between tide-marks and thence down 

 to 170 fathoms, the deepest water dredged. 



AmpJiiura JiUformis (Miiller) . 3 fathoms, Balta Sound ; Out Skerries Had- 

 dock-ground, and in St. Magnus Bay, 30-60 fathoms. 



Chiajii, Porbes. Off Balta ; on the Haddock-ground near the Out 



Skerries, and in St. Magnus Bay. 



eleyans (Leach) = Ophiocoma neglecta, Porbes. Tide-marks, to 40 



fathoms. 



Ballii (Thompson) = Ophiocoma Ballii and Goodsiri, Porbes. Common 



on hard ground in deep water, delighting to nestle in crevices of stones, 



shells, and corals. 

 Ophiopeltis securigera, Dub. & Korcn. Added to the British fauna in 1861, 



when a single specimen was dredged on the Haddock-ground, about 5 



miles north of Whalsey Lighthouse, in 40 fathoms. 

 Ophiocoma niyra (Miiller) = Ophiocoma gramdata, Porbes. 



