CALLOK.HYNCHUS ANTARCTICUS. 407 



to be "whimsical in disposing of these modes out of the general order, 

 diversifying them in such ways as to make a vast number of species in 

 most tribes ; not only diversifying the properties of a tribe, but making 

 such a combination of those properties in some tribes as is most distant 

 from the general combination ; uniting [in one] an operation belonging 

 to another tribe most distant from [that one] in all its other properties. 



The animal before us appears to be the most remarkable instance of 

 these observations of any I know. It seems to be a mixture of as great 

 a variety of properties of different tribes or genera as can possibly be. 

 It is a fish in all those properties on which the economy of life depends. 



Externally it has the tail of the shark, having the fin-part of the tail 

 on the under edge 1 . The ventral fins, which answer to the hind -legs in 

 quadrupeds 2 , are very similar to those of the shark, but are more fleshy 

 than common : as also are the arm-fins [pectorals], which are very 

 broad, and more fleshy than in fish in common, or in any of the ray- 

 kind. There are two fins on the back ; however, the anterior one is 

 rather further forwards, and has the spur, on its anterior edge like the 

 dog-fish. But, in other external appearances, it is not of the shark-kind ; 

 for it has but one opening from the gills, which is an oblong orifice as 

 in the eel, but which is covered by a fold or flap of the skin of the head : 

 nor is it similar in some of its essential parts ; for its gills are similar 

 to those of bony fish, not at all like those of the ray-kind. Its mouth 

 is like the mouth of no fish that I know ; nor is it similar at all to that 

 of the porpoise, to which the animal is similar in a most striking in- 

 stance 3 . It has a projection at its nose peculiar to itself, and its eyes 

 are [peculiar ?], as far as I could judge. It has no scales, but a soft 

 skin which is pied. Its intestine is that of the ray-kind. The female 

 has two oviducts, similar to those of the ray-kind, which appear to open 

 above the liver; at least I suppose so, from analogy, being in some 

 respects similar to those of the ray. 



These two ducts get to the sides of the abdomen, winding round the 

 liver, and descend along the back, coming nearer each other to the anus, 

 but where they open I could not discover, being too small for examina- 

 tion. There are two ovaria, one on each side of the spine, near the 

 upper part ; they are flat bodies somewhat similar to those of the dog- 

 fish. But what is the most curious of the whole is a union of the most 

 distant parts, and of course principles, that I know in Natural History. 

 It has two nipples 4 , as in the whale- class of animals, one on each side 



1 [The ' heterocercal ' form of Agassiz.] 



2 [A homology also appreciated by Linnaeus, in forming his order Apodcs.] 



3 [Viz. in the supposed nipples.] 



4 [The rudimental homologues of the ' claspers ' in the male.] 



