DRS. CARPENTER AND CLAPAREDE ON TOMOPTERTS ONISCIFORMIS. <>7 
disguise its form. Nor is this any exaggeration of the fact : for having sent the vessel t< 
an accomplished artist already named, Mr. Peter Syme, for the purpose of obtaining i 
delineation, I found, on reaching him, that he had been unable to discover the object 
However, by resorting to similar expedients as practised by myself, he could now repre- 
sent the most conspicuous parts of the animal. 
" Nearly three years afterwards, I obtained another specimen in November. Both 
occurred in a capacious jar of sea- water taken from about the same place, Newhaven 
Pier. But, with ample opportunities, none have been again found there. 
" Twenty years later, six specimens were obtained from the Isle of May, not less than 
thirty miles distant; and from the whole I have been able to gain some slight acquaint- 
ance with this singular animal — singular because human vision can scarcely discover, 
what is of sufficient size to expose every feature. Hence it is that there must always lx> 
slight discrepancies between the drawings of different artists." 
Of the two representations given of the animal in Sir J. G. Dalyell's 36th Plate, that 
which was drawn by Mr. Syme from the specimen first seen departs greatly from its tr 
proportion,— the pinnulated appendages, of which there are sixteen on either side, bein 
drawn much too long (as in the figure of MM. Quoy and Gaimard), whilst the second 
antennae are as much too short. The caudal prolongation in this specimen appeals to have 
been just beginning to show itself. The second figure, which appears to have been 
drawn from the specimens obtained at a later period, is a much truer representation of a 
more advanced stage of development, the length of the caudal prolongation being about 
one-third of that of the body. Some of the specimens are said by Sir J. G. Dalyell to 
have had only four or five, or seven, pairs of limbs. He remarks that the animal M can be 
preserved with difficulty, from being liable to entangle itself in every foreign substance, 
and is easily mutilated in its struggles for liberation. None have survived longer than 
twenty-four days ; they generally live only a week." We have have not ourselves succeeded 
in preserving them for more than the shorter of the periods j ust named. 
EXPLANATION OF THE PLATE 
Tab. VII. 
Tomopferis onisciformis. 
various 
Fig. 1. Posterior portion of the body, and caudal prolongation, of a female, showing the ova in 
stages of development, lying in the perivisceral cavity. Magnified 40 diameters 
Fig. 2. Caudal prolongation of a male, showing the testes a, a occupying the cavities of the rudimentary 
pinnulae. Magnified 65 diameters. ^ 
moi 
discharged externally, at b the orifice leading to the perivisceral cavity, and at c the larger 
ridged rosette of the ciliated canal. Magnified 150 diameters. 
Pig* 4. Biflagellated spermatozoa. Ma Q 
Fig. 5, Portion of the head, seen on its dorsal aspect, showing the ciliated epaulettes a, a 
Mag 
diameters. 
K 2 
