W. H. Leigh-Siiarpe 
265 
existed in this species. I am now certain that the true type of mandible is 
that which is figured in Fig. 3 A of the present paper, which closely approxi¬ 
mates to that of L. galei except in regard to the secondary teeth, and in this 
respect I am not positive that one is not lost in L. galei. There are however 
but three primary teeth instead of four. My error was due to the fact that 
the terminal tooth was lost, as is not infrequently the case, and apparently 
the next principal tooth also; the organ being slightly turned on its side the 
intermediate teeth were unrecognisable, and what I considered to be teeth 
increasing in size posteriorly are really the secondary teeth. The wearing 
En. 
2 ANTENNA 
Fig. 7. L. scyllicola, a detailed enlargement of the antenna (Romanowski): Ex. exopodite; 
En. endopodite; 01-5. (?) photoreceptors. 
away of distal teeth is not to be wondered at if they have to pierce the 
skin of the dogfish where it is covered by dermal denticles. 
Relationship. It appears to me that L. scyllicola and L. galei approximate 
to one another very closely, much more so than any other of the four species 
which I am at present considering. My opinion based upon the comparison 
of these species is that from the common Lernaeopoda stock, from which 
Lernaeopodina may have differentiated very early, L. scyllicola represents a 
central and most typical form from which L. galei and L. mustelicola sub¬ 
sequently descended, while I am inclined to think that L. globosa branched 
off from the stem prior to the evolution of L. scyllicola. The following diagram 
