698 



Ctoatfurji flf Natural ^ 



rode there accompanied by my host, and 

 purchased for the value of eighteen^ pence, 

 the head of an animal equalling in size that 

 of the Hippopotamus. Mr. Owen, in a paper 

 read before the Geological Society, has called 

 this very extraordinary animal, Toxodon, 

 from the curvature of its teeth. The fol- 

 lowing notice is taken from the proceedings 

 of that society : Mr. Owen says, judging from 

 the portion of the skeleton preserved, the 

 Toxodon, as far as dental characters have 

 weight, must be referred to the Rodent order. 

 But from that order it deviates in the re- 

 lative position of its supernumerary incisors, 

 in the number and direction of the curvature 

 of its molars, and in some other respects. It 

 again deviates, in several parts of its structure 

 which Mr. Owen enumerated, both from the 

 Rodentia and the existing Pacliydermata, 

 and it manifests an affinity to the Dinottie- 

 rium and the Cetaceous order. Mr. Owen, 

 however, observed, that ' the development 

 of the nasal cavity and the presence of frontal 

 sinuses, renders it extremely improbable that 

 the habits of the Toxodon were so exclusively 

 aquatic as would result from the total ab- 

 sence of hinder extremities ; and concludes, 

 therefore, that it was a quadruped, and not 

 a Cetacean ; and that it manifested an ad- 

 ditional step in the gradation of mamini- 

 ferous forms leading from the Rodentia, 

 through the Pachydermata to the Cetacea; 

 a gradation of which the Water-hog of South 

 America (Hydrochxrus capybara) already 

 indicates the commencement amongst exist- 

 ing Rodentia, of which order it is interesting 

 to observe this species is the largest, while 

 at the same time it is peculiar to the con- 

 tinent in which the remains of the gigantic 

 Toxodon were discovered.' 



" The people at the farm-house told me 

 that the remains were exposed, by a flood 

 having washed down part of a bank of earth. 

 When found, the head was quite perfect ; but 

 the boys knocked the teeth out with stones, 

 and then set up the head as a mark to throw 

 at. By a most fortunate chance, I found a 

 perfect tooth, which exactly fits one of the 

 sockets in this skull, embedded by itself on 

 the banks of the Rio Tercero, at the distance 

 of about 180 miles from this place. Near 

 the Toxodon I found the fragments of the 

 head of an animal, rather larger than the 

 horse, which has some points of resemblance 

 with the Toxodon, and others perhaps with 

 the Edentata. The head of this animal, as 

 well as that of the Toxodon, and especially 

 the former, appear so fresh, that it is difficult 

 to believe they have lain buried for ages 

 under ground. The bone contains so much 

 animal matter, that when heated in the 

 flame of a spirit-lamp, it not only exhales a 

 very strong animal odour, but likewise burns 

 with a slight flame. 



" At the distance of a few leagues I visited 

 a place where the remains of another great 

 animal, associated with large pieces of arma- 

 dillo-like covering, had been found. Similar 

 pieces were likewise lying in the bed of the 

 stream, close to the spot where the skeleton 

 of the Toxodon had been exposed. These 

 portions are dissimilar from those mentioned 

 at Baliia Blaiica. It is a most interesting 



fact thus to discover that more than one gi- 



f antic animal in former ages was protected 

 y a coat of mail, very similar to the kind 

 now found on the numerous species of arma- 

 dillo, and exclusively confined to that South 

 American genus. I may here just mention 

 that I saw in the possession of a clergyman 

 near Monte Video, the terminal portion of 

 a tail, which precisely resembled, but on a 

 gigantic scale, that of the common arma- 

 dillo. The fragment was 17 inches long, 

 11J in circumference at the upper end, and 

 8J at the extreme point. As we do not know 

 what proportion the tail bore to the body of 

 the animal, we cannot compare it with 

 that of any living species. But at the 

 same time we may conjecture that, in all 

 probability, this extinct monster was from 

 six to ten feet long." 



TOXOTES, or ARCHER-FISH. A 



genus of Acanthopterygious fishes, belong- 

 ing to Cuvier's sixth family of Squamipennet, 

 distinguished from its congeners by the 

 body being short and compressed, the dorsal 

 fin situate far back, the snout short, the 



lower jaw projecting beyond the upper ; the 

 mouth is crowded with small teeth, and the 

 opercula are finely toothed. The species ob- 

 tains its name from projecting drops of water 

 at insects three or four feet above the surface 

 of the water, which it seldom fails in bringing 

 down. 



TRACHELIDES. A family of Coleop- 

 terous insects, obtaining this name from 

 having the head, which is triangular or 

 heart-shaped, carried on a kind of neck, 

 which separates it from the thorax. The 

 body is soft, and the elytra are flexible. The 

 majority of this group live in the perfect 

 state upon different vegetables, devouring 

 the leaves, or sucking the juices of the flowers. 

 Many of them, when seized, depress the head 

 and contract the feet, as if they were dead. 

 Their colours are often very brilliant. We 

 refer for an example of them to the Can- 

 tharis yesicatoria, commonly known as the 

 Blistering-fly ; an insect of a shining green 

 metallic hue, mostly abundant in Spain. 



TRAP-DOOR SPIDER, The name ap- 

 plied to Spiders of the genera Cieniza and 

 Ac.tinopus, separated by modern authors 

 from the genus Mygale of Walckenaer, and 

 remarkable for forming in the ground a long 

 cylindrical tube, protected at the top by a 

 circular door, which is connected to the tube 

 by a hinge. Mr. Westwood remarks : " Of 

 all the habitations constructed by annulose 



