On a nondescript Aquatic Animal. 337 



security to the other, seeing they are almost cut in two by 

 their being brought into so close contact with the mouth of 

 their destroyer, and quite drained of their very vitals. 



Thus nature, as if to counteract her wonted profuse fe- 

 cundity in this diminutive scale of beings on the one hand, 

 seems on the other to have made this formidable nonde- 

 script adversary to thin the race. So tenacious is he of his 

 prey, that, having once fastened on, he will bear to be 

 drawn quite out of the water, and held for some minutes 

 suspended by the hold he has taken by the forceps ere he 

 will let go his victim ; and so determinateiy undaunted as 

 to bear to be lashed with a small twig, which he has the 

 hardiness to endure. The opening of his forceps seems to 

 fascinate his victims ; they become, as it were, transfixed 

 by torpor, and riveted to the spot, thoush naturally capable 

 of swimming much faster than their enemy. 



One ])articular more which I observed may not be amiss 

 to notice, which is, the ebbing and flowing of the blood, 

 which does not appear to circulate through ail the parts, but 

 by a kind of undulatory motion, or rather pulsation, pro- 

 ceeds and recedes towards and from the head to about half 

 way down the body in one entire mass. Though without 

 doubt the whole frame is visited by this vital principle, yet 

 it is in such small quantities as to elude the most minute 

 inspection I could bestow upon it; and if the quantities 

 were not, indeed, very minute, it could not but be visible 

 through the semi-transparency of the body; for it is not 

 limpid like water, but of so sanguine a tint as to give the 

 middle part of the body a black appearance. 



Notwithstanding these minute particidars which I have 

 made myself acquainted with, I shall not venture to deter- 

 mine what class it ranks in, because it seems to participate 

 of several, or at least to possess members and faculties in 

 common with two or three; and as I could not gain any 

 information on this head from my books, though there seems 

 somewhat very characteristic in this creature, I thought it 

 might not be impertinent or displeasing tosomeof your read- 

 ers to have the best information I could extract from strict 

 observation (;f its functions and amusements. And although 

 it comes without the minuteness and accuracy of zoological 

 classification, yet I believe I am perfectly correct in every 

 particular stated, in which if I meet your concurrence it is 

 very much at the service of your readers. 



Description of the Drawing. (See Plate II.) 



Fisr. 1. View of the back parts, magnified. 



Fig. 



