WORM PIPE-FISH. 4-51 



preceding page represents this fish but little less than its 

 natural size. It possesses when adult no fin except that on 

 the back, which in the specimen I examined contained thirty 

 rays. The nose is very short, turned a little upwards ; 

 the eyes prominent ; from the point of the jaws to the pos- 

 terior edge of the orbit, and thence to the end of tlie opcr- 

 culum, the distances are equal ; the length of these two 

 portions together, compared to the whole length of the fish, 

 is as one to twelve ; the form of the body nearly cylindrical ; 

 the vent is situated at the end of the first third of the whole 

 length, with a series of nineteen plates before it, and in a 

 vertical line, with three-fourths of the dorsal fin behind it ; 

 from the vent the body tapers gradually all the way to the 

 tail, which ends in a point ; the number of plates forming the 

 series between the vent and the tail-end, about fifty. The 

 surface of the body is more smooth than in the two species 

 previously described, and the colour is dark olive green. 



In 1837 the late Professor B. Fries, of Stockholm, pub- 

 lished an interesting paper on the metamorphosis which takes 

 place in this species : an interesting fact hitherto unobserved 

 to the same extent in the class of Fish, namely, that the 

 young of this species at their escape from the egg have the 

 entire tail covered with a fin-like membrane, which extends 

 partly up the back, and also along the under surface as far as 

 the anal aperture : the little fish at this stage possesses also 

 pectoral fins. Except the portion required to form the per- 

 manent dorsal fin, all these, at a subsequent unknown period, 

 are thrown off in a way similar to that of the larvse of frogs 

 rejecting their tails. The absorption of the pectoral and 

 caudal fins is the novelty in this case : the existence and sub- 

 sequent absorption of part of the dorsal and anal membrane 

 was previously known to occur in the young of the Salmon. 





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