198 A HISTORY OF RECENT CRUSTACEA 
so as to make a perfect orbit and to cover the ocular seg- 
ment. Itis said to have the antenne of Palinurus, the 
trunk-limbs like those of Scyllarus, the carapace like that 
of Astacus, and the pleopods like those of Scyllarus, so as to 
form a truly inosculant genus. The type species is Synazes 
hybridica, Spence Bate, from the West Indies. Spence 
Bate himself observes that ‘ Palinurellus, von Martens, ac- 
cording to that author differs from Synaves in having the 
posterior pair of pereiopoda chelate in the female,’ but does 
not explain how that can be any distinction, if, in Synazes, 
‘the pereiopoda are like those of Scyllarus,’ as he declares 
them to be, for in Scyllarus also the last pair are chelate 
in the female. The student must be prepared sometimes 
to find it as difficult to reconcile authors with themselves 
as with one another. Under the circumstances one may 
accept the decision of Dr. Boas, quoted with evident ap- 
proval by von Martens, in 1882, that Synazes is a synonym 
of Palinurellus. 
The strange form known as Phyllosoma was at one time 
regarded as belonging to a distinct genus, but is now 
known to be larval, by such marks as the median eye, and 
the rudimentary character or unjointed condition of the 
various parts. A considerable number of specimens of 
Phyllosoma were obtained by the Challenger, of sizes 
varying from the seventeenth of an inch up to an inch and 
two-fifths, the latter being larger than some specimens of 
Palinurus that have attained the permanent form. In a 
general way the Phyllosoma forms may be assigned to 
ditferent stages in the development of the Scyllaride and 
Palinuride, bat to assign the successive stages to par- 
ticular species does not seem always possible at present, and 
in especial there appears to be an awkward gap between 
the most advanced Phyllosoma and the earliest post-larval 
form. No such perplexity, however, affects the first 
larval form, or brephalos, when actually extracted from 
the ovum. A specimen of this kind is shown on Plate IX., 
in Spence Bate’s figure of a juvenile Palinurus vulgaris. 
