312 REPORT—1868. 
time over its thorough investigation ...; and so by the help of acetic 
and chromic acids and liquor potasse, I have succeeded in very fairly 
unravelling the structure of your Polyzoon. It is a true Hippocrepian 
form, as entirely and typically so as Plumnatella—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 coenccium, 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 ccencecium, 
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 Rhabdopleura as sufficiently significant and distinctive.” 
—Allman in litt. Outer Haaf off Unst, in 93 fathoms. 
Clas ECHINODERMATA. 
The Crinoidea, Ophiuroidea, and Asteroidea in the following notes are 
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 Hchinoidea and Holothuroidea, I give references where the 
nomenclature of Forbes’s ‘ British Starfishes’ is not sufficient to indicate the 
species, 
Order CRINOIDEA. 
Antedon rosaceus (Linck). In the Voes and thence down to 40 fathoms, 
not uncommon, and attaining an unusually large size. Very abundant 
on Laminarix, in Bressay Sound, off Lerwick. 
Sarsti (Diiben & Koren). 80-100 fathoms, 40 miles east of Whalsey 
Lighthouse ; very local, but gregarious where found. 
Order OPHIUROIDEA. 
Astrophyton Linckii, Mill. & Trosch=A. scutatum, Forbes. Off the west 
coast, in very deep water (vide Forbes, British Starfishes). It has not 
been procured during the recent dredgings off the cast and north coasts, 
nor do the fishermen on those sides of the island appear to be acquainted 
with the species. 
Ophiothrix fragilis (Miller)= Ophiocoma rosula and minuta, Forbes. Haying 
a very great range in depth, living between tide-marks and thence down 
to 170 fathoms, the deepest water dredged. 
Amphiura filiformis (Miller). 3 fathoms, Balta Sound; Out Skerries Had- 
dock-ground, and in St. Magnus Bay, 30-60 fathoms. 
— Chiajvi, Forbes. Off Balta; on the Haddock-ground near the Out 
Skerries, and in St. Magnus Bay. 
elegans (Leach) = Ophiocoma neglecta, Forbes. Tide-marks, to 40 
fathoms. 
Ballii (Thompson)= Ophiocoma Bailii and Goodsiri, Forbes. Common 
on hard ground in deep water, delighting to nestle in crevices of stones, 
shells, and corals. 
Ophiopeltis securigera, Dib. & Koren. 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 nigra (Miiller) = Ophiocoma granulata, Forbes, 
