260 
Lernaeopoda 
of spines not at all clearly defined, the teeth of which appear to grade into 
a general roughness of the cuticle which is distributed over the joint. The 
basal joint not only has the two usual cushions of spines on its inner side, 
but is provided with three other cushions, which, as far as I know, have 
escaped the notice of other investigators, one on the outer edge of the proximal 
end, one on the outer edge of the distal end and the third a very large spinous 
area where the appendage joins the body. Of the usual cushions on the 
inner margin, the more distal one opposes a rounded cushion of spines whose 
exact locality is still uncertain, but which appears to be situated on the 
animal’s body, on peculiarly shaped ridges provided for the purpose; the 
proximal cushion is situated on a projecting boss at the extreme base of the 
joint, an unusual location not found in the other species, so that it very 
effectively opposes and in action touches its partner. There is no spine or 
hook between the cushions on the inner margin as in L. scyllicola. 
jj* vj/ jjy 
The following table contains a comparison between the four common 
species of Lernaeopoda $ (vide Fig. 1). 
Species 
Host 
Location 
Occurrence . 
Length of: 
(1) Cephalothorax ... 
(2) Trunk. 
L. Scyllicola 
Scyllium canicula 
Extra-cloacal 
region, pelvic fins 
and claspers 
On practically 
every male dogfish 
2 mm. 
5 + 2=7 mm. 
Ratio of (1) to (2) 
(3) 2nd maxillae (arms) .. 
(a variable character) 
Ratio of (3) to (2) 
(4) Ovisacs... 
Ratio of (4) to (2) 
(5) Abdominal appendages 
Ratio of (5) to (2) 
Ova: Rows ... ' .. 
No. in a row .. 
Bulla 
f 
7 mm. 
1 
5 to 7 mm. 
f= (nearly) 
3 mm. 
3 
T 
4 to 0 
22 to 23 
Large, stud-like 
L. Galei 
L. Globosa 
L. Mustelicola 
Galeus vulgaris 
Extra-cloacal 
region, pelvic fins 
Scyllium canicula 
Mustdus vulgaris 
and claspers 
Nasal fossae 
Pelvic region 
Common 
Eairly common 
(? Common) 
Over 1-5 mm. 
Nearly 2 mm. 
2 mm. 
7 to 9 mm. 
1 (Head ± r to trunk) 
+ over 2-3 mm. 
2+4 = 6 mm. 
3 
g 
i 
1 4 
3 
3 
4 to 5-5 mm. 
4 mm. 
2-5 mm. 
11 
T4 
i 
5 
T7 
6 to 10 mm. 
Over 2 mm. 
4 mm. 
f = (nearly) 
= (nearly) 
I 
Nearly 2 mm. 
0 5 mm. 
1 mm. 
2 
7 
1 
4 
* 
4 to 6 
6 to 8 
4 
29 to 30 
12 
18 
Moderately large, 
Small, the second 
Moderately large. 
stud-like 
maxillae also ending in 
two expanded discs 
stud-like 
The point of attachment of Lernaeopoda spp. upon the host in its bearing on 
the consequent length of the “arms ” (second maxillae). 
Species Host Location Length of “arms” 
L. elongata Lamna cornubica Eyes 20 mm. (longer than the trunk)*. 
L. globosa Scyllium canicula Nasal fossae 4 mm. (f length of trunk) but this 
is a very small species 
