Dr. Cantor on the Foetus of Zygaena laticeps. 373 



seldom seen, and attains to about eleven feet in length, and 

 Z. laticeps, which is exceedingly numerous, and apparently of 

 smaller size than the former. On the 15th of September 1844, 

 some Chinese fishermen captured off Prince of Wales Island a 

 gravid female Z, laticeps, hf far the largest which has come under 

 my observation, of the following dimensions : — 



Entire length of the fish 4ft.4in. 



Breadth of the head (the anterior margin) ... 2 ft. 1^ in. 



On being opened there appeared eighteen living young ones, 

 of which number seven were males, distinguishable by the anal 

 appendages, and eleven females. All eighteen were of nearly 

 equal size, and of the following dimensions : — 



Entire length of the body 1ft. 1^ in. 



Breadth of the head (anterior margin) 6 in. 



The relative proportions of the head and body consequently re- 

 main nearly the same in every stage of growth. The lateral pro- 

 cesses of the head were in the fcetus considerably bent in a back- 

 ward and inward direction, imparting to the head the shape of a 

 broad arrow, whereas these processes after birth form with the 

 body a right angle, which makes the fish resemble a double ham- 

 mer, or the letter T. In the foetus the lateral processes are en- 

 tirely membranous, except a narrow cartilaginous cylinder which 

 encases the optic nerves, and which is so pliable that it does not 

 prevent each lateral process from lying in close contact with the 

 sides of the body, and thus they take up but comparatively small 

 room, and offer no obstacle under parturition. None of the foetuses 

 were provided with branchial filaments. The teeth, in the adult 

 fishes comparatively small, were barely perceptible to the touch. 

 The colours were precisely similar to those of the adult. Zygcena 

 laticeps in its foetal state, and shortly after birth, answers in every 

 respect to the description, and resembles so exactly the deli- 

 neation of Z. Blochii, represented by M. Valenciennes, Mem. 

 du Mus. ix., that in all probability the original of Bloch, pi. 117, 

 and of M. Valenciennes, which has afterwards been copied by 

 myself and lately by Mr. Yarrell, was a foetus or very young spe- 

 cimen of Z. laticeps. As neither Bloch nor M. Valenciennes ap- 

 pear to have given the dimensions of the fish figured, it is impos- 

 sible to decide the question till the actual size of their original 

 has been ascertained. The smallest specimen which I have ob- 

 served of Z. laticeps in its perfect state — I mean in which the 

 lateral processes of the head form a right angle with the body — 

 measured \~ ft. in total length. From this I infer, that the 

 lateral processes of the head, which in the foetus branch off from 

 the head under a sharp angle, pointing backwards, change their 

 position and acquire firmness at no remote period from the birth. 



