INVERTEBRATA, CRYPTOGAMIA, MICROSCOPY, ETC. 809 



truncate, the oral disk provided with fifteen oblong depressions, con- 

 taining the saino number of i)apilliform tentacles, and alternating 

 with fifteen tubular processes also on the disk ; the posterior eiid is 

 produced tail-wise, tlie cloacal opening surrounded by five papilhe ; 

 the skin carries perforated papilho provided with peculiar calcareous 

 bodies, consisting of five to six stellately arranged sjioon-like rods 

 from tlio centre of which project tlic anchors ; feet absent ; two anal 

 appendages. A. J<:Jfreij8ii was found chiefly in the most northern fiords 

 of Finmark ; the other species at IT 27' N. lat., 2iP 51' E. long. 



The other species recorded by them are Myriotrodiua Rinlcii 

 Stcenstrup, M. hrevis Huxley, M. Itinldi Theel fwliich differs from 

 Steenstrup's species in having more tentacular cirrhi, &c.j, Oliyotrochus 

 vitreua Sars, Trochostoma boreale Sars, T. arcticum Marenzeller. 



Synthetic Type of Ophiurid.* — Professor P. Martin Duncan 

 describes a very remarkable Opliiuran which forms part of a collec- 

 tion obtained by Dr. Wallich, during his voyage in II.M.S. ' Bulldog,' 

 in the year 18G0, off the coast of East Greenland. The Ophiuran was 

 presented by him to tliis Society. 



The Opliiuran — PolDpliolis echinala — -j^^j- inch long, and tlie body 

 ■j\j- inch in diameter, came up with the sounding apparatus from off tho 

 sea-floor at a depth of 228 fathoms, about 50 miles north and east of 

 Capo Valloe, East Greenland, and about 200 miles from Capo Fare- 

 well, date July 10, 18G0, lat. 60^ 42' N., long. W 42' W. The 

 "cup" came up full of fragments of granite and felspar, to which 

 were adherent small corallines. Some of them were very delicate, 

 and their perfect condition indicated an undisturbed state of the 

 bottom water where they occurred. There was a sudden decrease of 

 depth close to the spot, and the water shallowed 578 fathoms in 

 three miles. 



Although a young form, this specimen presents tho normal 

 structures of an Ophiuran, and it is in no way deformed or abortive. 

 The extreme simplicity of tho oral apparatus is in itself remarkable ; 

 there are true teetli, but the spines on the side moutli-shields are tho 

 only mouth pa2)ilhc, and they are so called because it is the fashion, 

 erroneously, so to call all growtlis from the sides of tho jaw-angles 

 and side mouth-sliields. The use of the small spines on the side 

 mouth-shields is that of tentacle-scales, and they can have nothing to 

 do with alimentation. This remark holds good in tho majority of 

 instances where the spine arises from tho jaw, close to tho side 

 mouth-shield and tentacle opening. 



There are no tootli-papilla), and the knob-liko projection witliin 

 the jaw plate beneatli the true teeth, so like that of some Amphiurans, 

 is not seen on all tlie angles. It comes doubtfully, however, within 

 tho description of mouth-papillro, and appears to be a true tootli. 

 The regularity of the pentagon surrounding tho oral apparatus is 

 very striking, and so is the extreme separation of the jaw-angUs, 

 much of wliieh, however, may be duo to ixid-morlem contraction. All 

 tho plates on tho upper surface of tho disk have separate, broad baaed, 



* • Journ. Lina. tioc.' (Zoul.), xv. (lS8'J) i». 16. 



