DI A ST YUS. 
149 
the sixth furnished with two limbs, ending in double sty- 
lets; central tail-piece long, produced into a style. A 
curious genus, the first character in the general appearance 
of which, as Mr. Spence Bate remarks in his elaborate 
Paper, ^ is that of its being a mutilated creature ; the re- 
duced form of the members generally gives the species the 
appearance of wanting many of their limbs. Agassiz and 
others have said that these creatures are the young of 
certain genera of Macroura , such as Aljohaus, Palrzmon , and 
Hijojoolgte, but Mr. Harry Goodsir has clearly shown that 
they are adult animals, perfect in themselves ; and that 
they belong to the Stoma/poda is proved by Mr. Bate, not- 
withstanding their being sessile-eyed. 
Mr. Goodsir remarks that the various species swim with 
very great rapidity ; and on stopping, they fall to the bottom 
on the sand or gravel, without attempting to lay hold of 
anything, seldom using their feet as a means of prehension. 
He has often placed the point of a needle on their thorax, 
and pressed them down into the sand ; the animal immedi- 
ately frees itself, with very little apparent trouble, by means 
of its tail. The end of this is placed against the needle, 
with one of the styles on either side of it* and by pressing 
* Arm. and Mag. Nat. Hist., June 1856. 
