eT, ae 
THE MARSIPOBRANCHII. 1338 
than with the Petromyzontide; and this, in view of 
certain of Parker’s determinations having been based on 
subtle differences in histological structure of the cartilages 
themselves, is sufficient justification for reconsidering 
the question.* 
Comparison of Furbinger’s and Parker’s work with that 
of Huxley leaves little room for doubting the homology of 
the cartilages lettered cn. and p.q. in figs. 1 and 2, Pl. [x 
with the lateral cornu of the hyoid and the sub-ocular 
arch (palato quadrate) of the higher vertebrata; while the 
median rod which les immediately beneath the Hag’s 
olfactory organ recalls, in all its essential relationships, 
the expanded plate of the Lamprey (p.d. of figs.). The 
chondrocranium of the Hags is on either side elongated 
and laterally expanded, in relation to a freely movable 
cornu (/. fig. 2) which enters the adjacent tissues and was 
termed by Parker the ‘‘ prepalatine”’ cartilage. In its rela- 
tionships to the super ficial branches of the trigeminal nerve 
this ‘‘ prepalatine”’ closely corresponds with that which 
Huxley claimed (loc. cit. p. 427) as Meckel’s cartilage in 
the Lamprey, and with that I hold it to be homologous, 
notwithstanding Parker’s view to the contrary.+ If this be 
so, further comparison of the Lamprey and Anuran Tadpole 
shows that the quadrate articular element instead of being 
represented in the Myxinoids by a portion of the sub-ocular 
arch lying behind the orbit, as Parker supposed,t is in 
much greater likelihood included in the aforenamed elon- 
gated lobe (qu. of figs. 1 and 2) which les in front of it. 
The marked forward disposition of the quadrate articulation 
* Some critical remarks upon Parker’s observations on the branchial skel- 
eton will be found in Nestler’s paper already quoted (ante. p. 127). This 
monograph deals satisfactorily with several more moot points in the anatomy 
and development of the Lamprey. 
tloc. cit., Pe 452. 
floc. cit pi 378. 
