W. H. Leigii-Siiarpe 
33 
behind. When first they arise in the meta-nauplius stage, these appendages 
are clawed and similar to the maxillipedes (in other species). In the free- 
swimming or first copepod stage, when the larva attaches itself to the host, 
the 2nd maxillae become fastened to the proximal end of the frontal filament. 
Fig. 3 A is drawn from a flattened preparation, so that the bottom portions of 
the discs appear to overlap, and in it I have endeavoured to show, that from 
the centre of the concavity of each disc a prominence arises, which on fusing 
with its partner from the other disc passes almost imperceptibly into the 
bulla; thus, in Fig. 3 B (in side view) only half the bulla is shown to be 
attached. The bulla is embedded beneath the cellular tissues of the host. The 
inner half of the disc is in contact with the inner half of its partner, while the 
outer or more distal half overlaps a papilla of the host in which the bulla is 
embedded, the papilla being induced by the clasping together of the discs. 
The result is the same as in the bidiscoid condition described by Kane in 
L. bidiscalis, though from his figures the details appear to be different. It is 
extremely difficult to detach parasites intact from Elasmobranch claspers; 
invariably the bulla is left behind. Now Kane collected all his specimens 
from the tips of the claspers of Galeus vulgaris. As no other species of Lernaeo- 
poda is without a bulla I throw out the suggestion that L. bidiscalis may possess 
a vestigial bulla also, and it is within the bounds of probability that Kane 
overlooked it. 
The Maxillipedes (Fig. 3 C) are clawed appendages situated between the 
bases of the second maxillae, and consist of a basal joint, which is stout 
instead of being slender as in L. scyllicola, and well supplied with powerful 
muscles which move the terminal joint and flex it down against the inside 
of the basal joint which is provided on the inner side with two but slightly 
developed rounded cushions (as compared with L. scyllicola), covered with 
minute spines. Between these cushions is a small spine in the position where 
L. scyllicola bears a large curved hook. The terminal joint, though slender, is 
not so long and slender as in L. scyllicola, and terminates in a long abruptly 
hooked claw, with two accessory claws at its base on the inner side. On the 
outer side of the terminal joint there is a small spine at the base of the large 
claw, and, also, at the'proximal end, in an unique position, a further specific 
spine (Fig. 3 C s'). Near the proximal end of the terminal joint on its inner 
side there is barely recognisable a rounded cushion of small spines, which, 
when the joints are brought together, would be nearly, but not quite, opposite 
the more distal cushion on the basal joint. The maxillipedes have lost their 
function as attaching organs, and are used only for pulling the head down to 
the host while the animal feeds. 
The Mouth parts, lips and Alimentary canal are as described in 
L. scyllicola. 
The Reproductive System is in the main as described for L. scyllicola 
save that the oviducts leave the ovaries at the anterior outer borders instead 
of half way along their sides, The ovisacs, however, are characteristic. Farfrom 
Parasitology xi 3 
