CYAMUS OVALIS. 93 
According, also, to M. Roussel de Vauzeme, Cyamus 
ovalis, as well as C. gracilis, are only found upon the tu- 
bercles of the chin, lips, and upper jaw of the whale, and 
especially upon the larger tubercle of the head, which 
the whale-fishers call the crown, near the blow-holes, and 
the horny excrescences with which it is surrounded. 
Sometimes, indeed, C. ovalis is found in such vast num- 
bers in this last situation, that at a considerable distance 
the patch of white colour, produced by their presence, 
may be observed when the whale comes to the surface to 
breathe. In this situation the individuals of C. ovalis 
arrange themselves with considerable regularity, by 
which they are distinguished from C. gracilis, which are 
scattered about more irregularly. 
The young of C. ovalis, as figured by M. Guérin 
Méneville, in the “ Iconographie du Régne Animal,” is 
more regularly elongate-ovate than the young of C., ceti, as 
figured above by ourselves, with the legs almost cylin- 
drical, the fourth joint but moderately dilated ; indeed, 
according to M. Milne Edwards (Ann. Sci. Nat. vol. 11. 
p- 329), “Les jeunes Cyamus ont une forme suelte et 
elancée,” all the segments being perfectly alike, re- 
sembling portions of a cylinder with the legs ‘ gréles, 
? 
cylindriques, et parfaitement extensibles;” and with the 
branchial vesicles not more developed than in Prodo, 
Caprella, &c. 
