510 



RADIOLA RAIA. 



molluscous and crustaceous animals. The other one 

 is very partial to the same kind of food when in con- 

 finement, and therefore has its food and feeding in a 

 state of nature little known. They very probably 

 bear a good deal of resemblance to those of this one. 

 This is rather a larger animal than the common 

 racoon, but it has the tail shorter. The fur upon it 

 is shorter, but closer, finer, and more valuable than 

 that on the other. Its general tint on the back is 

 brownish-ash, produced by the mixture of black, grey, 

 and yellow ; the black predominates on the middle of 

 the back, and also on the head and neck, but the 

 general tint becomes lighter toward the sides, where 

 the dull brownish yellow is nearly entire ; the feet are 

 brown ; and the tail, though short, is marked with a 

 greater number of black rings than that of the com- 

 mon racoon ; the end of the nose is black ; and a 

 blackish-brown patch surrounds the eyes, reaches 

 back on each side nearly to the ears, and the two 

 portions meet together on the top of the head ; the 

 cheeks, sides of the jaws, tore-neck, breast and belly, 

 are yellowish-white. As this species of racoon is 

 less in the woods, and more in the open places, than 

 the former, and as the shores of the wooded parts of 

 South America are the places most easily explored, a 

 little more is known of the habits of this one in wild 

 nature than of those of the other. According to the 

 accounts, its breeding-time is in May, and the litter 

 generally consists of three. The two species have, 

 however, been much mixed up with each other in the 

 popular description ; and the racoons and the coatis 

 nave sometimes had each other's descriptions applied 

 at rather cross-purposes. Altogether, the animals of 

 South America require to be carefully examined, as 

 the manners of most of them are peculiar, and very 

 Jittle known. 



RADIOLA (Dillenius). A small curious annual, 

 a native of Britain, called allseed. The flowers are 

 tetrandrous, and the plant belongs to LineeE. 



RAFFNIA (Thnnberg). A genus of undershrubs 

 from the Cape of Good Hope, belonging to Legu- 

 minosce. The species, of which there are several, 

 succeed well with ordinary greenhouse treatment. 



RAIA, the rays or skate, or more correctly per- 

 haps, RAIID^, the skate family a very remarkable 

 family of Chondropteri/gous or cartilaginous fishes, 

 resembling in their physiology the shark family much 

 more than any other ; and following in their forms 

 the angel-fish or rnonk-fish of that family. There are 

 very great differences between them in the details of 

 their appearance and form, as well as in the estima- 

 tion in which their flesh is held as food ; but notwith- 

 standing this, there is a strong family likeness that 

 runs through the whole of them. 



They form a family hardly less numerous than 

 that of the sharks. Their bodies are flat and much 

 extended in breadth, with the exception of the tail, 

 which is usually long, slender, and round, and very 

 frequently carries the dorsal fins as well as the caudal 

 one. Though the body of the rays is often much 

 flatter and broader than that of the flounders 

 and other flat fish properly so called, it is not flat- 

 tened in the same manner. The flat fish is com- 

 pressed, that is, itis narrow and deep ; the ray, on the 

 other hand, is depressed, or broad and shallow. There 

 is accordingly no twist in the head or neck of a ray, 

 and the whole body of it can be symmetrically di- 

 vided on the mesial plane. The great breadth con- 

 sists in the extraordinary development of the pectoral 



fins, which extend along the' sides and run into, and 

 sometimes in advance of, the snout. They do not 

 keep to the banks and the bottoms as the Hat fishes 

 do, but range far to sea, and are, like the allied family 

 of the sharks, powerful swimmers. They almost all 

 grow to a great and sometimes to an enormous size ; 

 there really not being any known limit to the size, or 

 even the age of any one of them. The broad part 

 is frequently of a sort of rhomboidal form, with two 

 angles in the snout and_base of the tail, and other two 

 in the longest parts of tiie pectorals. The general 

 form resembles that of a paper kite, tail and all. The 

 action of their enormous pectorals is so powerful in 

 the water, that they have been compared in that ele- 

 ment to the birds of prey in the air ; for as these 

 drive along the sky for long distances, so do the 

 others range over the breadth of the wide seas and 

 oceans. 



The backs of the rays are variously coloured, but 

 the under sides of all are white. The eyes and the 

 air-holes are on the upper surface of the head : and 

 the nostrils, mouth, and openings to the gills on the 

 under side. From the position of the eyes, it is by no 

 means likely that they can be of much use to the ani- 

 mals in directing the mouth toward the prey. But the 

 mouth is powerful as a prehensile instrument ; and 

 teeth, which are the only bones in the body that 

 acquire the consistence even of true bone, are fur- 

 nished with very hard enamel ; though in many of 

 the species, there are very hard spines upon various 

 parts of the back, the use of which in the economy of 

 the fishes is not very well known. 



The gill openings are situated behind the mouth, 

 and they lead to cavities in which the gills remain 

 fixed. The blade-bones of the pectoral fins are arti- 

 culated upon, or rather soldered to, the spinal column, 

 farther backwards than where the gills are situated ; 

 and though the whole motions of the fish are motions 

 of elastic cartilage rather than of articulated bones, 

 they are powerful, rapid, and not nearly so fatiguing 

 to the animals. The tail, which generally has some 

 twisting motions, and is pretty much produced, is by 

 no means an inefficient swimming instrument ; although 

 the great pectorals, from their flexibility, are no doubt 

 efficient in producing forward motion, as well as in 

 ascending and descending. Though in the ordinary 

 arrangements of the class, the rays stand near the 

 end, as differing widely from the bony fishes, of which 

 Cuvier very properly takes the perch family as the 

 leading one, and the common perch as the typical 

 species ; yet in some parts of their physiology they 

 stand higher than even those typical fishes, and may 

 be considered as approaching in their characters to 

 some of the batrachian reptiles, more especially in 

 their eggs, which are discharged from the body of the 

 female in an impregnated state ; and in their skins, 

 which are smooth and without proper scales like 

 those of fishes, but have a tendency to be more or 

 less roughened by spines and tubercles of bony mat- 

 ter. Their skins are lubricated with a copious 

 musical secretion. It is probable that their senses 

 of hearing and sight are pretty good ; but it is cer- 

 tain that the sense of smelling is the most acute one, 

 and the one upon which they chiefly depend for find- 

 ing their prey. The union of the sexes is real, 

 though not performed in the manner of land animals. 

 This fact has been well ascertained ever since the 

 days of Aristotle ; and it has also been pretty well 

 ascertained that the discharge of the eggs is gradual, 



