Fishes. 4673 



ciennes to the three subfamilies of the Salmonidae is a partial law, 

 applicable probably to some Continental species, but inapplicable to 

 the great family of the Salmonidae as they now exist in the waters of 

 the globe. Now, the Philosophy of Zoology, based on the Transcen- 

 dental in Anatomy and Physiology, requires higher generalizations 

 than those used by and of use to the merely practical man, A wide 

 inquiry into the dentition of serpents taught me this fact many years 

 ago. 



R. Knox. 



Miessen House, Upper Clapton. 



Memorandum of the Tadpole Fish. — I have lately observed among the sprats 

 brought to Billingsgate Market an occasional specimen of the tadpole fish (Raniceps 

 tHfurcatus). My attention was called to the subject by my son, a boy of eight, bring- 

 ing me one which he had picked out from among a parcel of sprats, and this inducing 

 me to look more carefully at the sprats exposed for sale, T am led to the conclusion 

 that this odd-looking fish is not so excessively rare as is generally supposed; and I 

 wish particularly to direct the attention of ichthyologists to its occasional occurrence 

 amongst sprats. The extreme length of a specimen which I minutely examined was 

 5^ inches, and its circumference close behind the insertion of the pectoral fin 4^ inches ; 

 the length of the head to gill-opening as 1 to 3j of the entire length ; from the tip 

 of the nose to the tip of the pectoral fin as I to 2^, or very nearly one-third of the 

 entire length. The colour was smoky brown above, paler beneath ; the skin covered 

 with slime, as in the eel, and presenting no indication of scales, under a lens of half- 

 an-inch focus. I mention this because the scales have been minutely described by 

 Dr. Johnston, and I know not whether my observation proves my own inadequate 

 power of examination, or that the scales are not present at the younger age at which 

 my fish was taken. The number of fin-rays was as under: — 



1st D. 1 : 2nd D. 56 : P. 20 : V. 5 : A. 53 : C. 34 : 

 thus in every instance being less than recorded by Pennant. The first dorsal was a 

 slender flexible spine unaccompanied by any membrane, and the ventrals were also 

 flexible spines of different lengths, and only partially united by membrane. When the 

 little fish had become somewhat dry, the " pea-like tubercles '' behind the pectoral fin, 

 to which Fleming alludes as distinctive of Raniceps Jago, and Johnston as possessed 

 by Raniceps trifurcatus after death, were very manifest both to the eye and finger. I 

 may perhaps be pardoned for remarking with reference to the discrepancy in the num- 

 ber of fin-rays, that counting of them must not be considered as absolutely distinctive 

 of specific difference, seeing that age, sex, or size of the fish, or the skill of the enu- 

 merator, may cause discrepancies such as those above noticed. — Edward Newman. 



