On a nondescript Aquatic Animal. 135 



while those of the oxides which have not brilliancy contain 

 at most from 13 to 14 of that principle. 



Two incontestable advantages result, then, from the pre- 

 paration of crystallized red oxide of mt rcury. 



1st, An increase of the product of that oxide, the mean 

 tenn of which is five per cent, more than when it is not 

 brilliant. 



2d, The impossibility or at least great difficulty which 

 avarice may experience in adulterating this product of art 

 by red oxide of lead. 



XXI. Facts relative to a nondescript Aquatic Animal. 

 By Mr. John Snart, Optician. 



To Mr. Titloch. 



SIR, 



JlIerewith I send you the exact drawing of a very sin- 

 gular aquatic creature 1 have lately discovered residing in 

 ponds in which the frog, &c. is generated from the first 

 rudiments or spawn of the parent and brought forth in the 

 tadpole state; in which stage of being it becomes the prey 

 of the said creature ; without the persecution of which, I 

 am persuaded frogs would infinitely move abound than at 

 present. 



The creature in question is of a most curious construc- 

 tion; having six legs, with the feet armed with talons, two 

 palpi or feelers, and four antenna; with a bifurcated plu- 

 mated tail. The body is divided into ten scmi-crustaceous 

 lobes somewhat like the armadillo (exclusive of the head 

 and neck, which form two more), by means of the joints of 

 which he is enabled to inflect himself into almost any posture. 

 The head is flatted like the scollop, and broad ; the mouth 

 is of the whole width of the head ; and proceeding from the 

 sides of the superior mandible or upper jaw spring two ten- 

 tacula-likc forceps, which it opens or closes at pleasure ; 

 these are curved and pointed like those of the forficula or 

 common earwig, and with these it seizes its prey, of which 

 the tadpole seems to be the principal favourite. Though 

 tadpoles are frequently found much larger than it, yet it 

 pursues them with the greatest coniidcncc. When it over- 

 takes them it punctures their skin with its forceps, and, 

 after lacerating them so as to fetch blood, drags them 

 towards its mouth, into which it receivc>t5 the effusion. 

 I 4 kSo 



