70 ‘TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 
altered, but in one or two specimens the notch in the 
basal part of the hind margin, as in C, is apparent. 
C. Large females with ova. Eleven specimens, 
75 to9 mm. Nebeski’s figure, f. 2. There is a gradual 
transition from B to C in size, depth of notch, and 
acuteness of palmar angle. 
It will probably be admitted, on comparing B with 
C, that the former has become sevually but not 
structurally mature. This is an important and 
disquieting fact for systematists, as many species have 
been separated on smaller differences than these. As far 
as size is concerned, I have noticed the same thing in 
the allied genus Jschyrocerus;* also in Calliopius 
leviusculus (Kréyer).* 
The : Males. 
The development of these, as indicated by the second 
gnathopods, is somewhat obscure. ‘They are not easily 
distinguishable from females until they reach the 
penultimate stage. From this Nebeski states that they 
follow two distinct lines of development, viz., 
(a) loc. cit. fig. 44, Im, m*, which he supposes to moult 
into the large adult form Im® (G in our plate), but of 
which I have not seen an example from any part of the 
Liverpool district, the nearest being that figured at EH. 
Our fig. D shows the 2nd gnathopod in course of the 
last moult, the distal dark-coloured part being the part 
to be shed, on the hind margin of which this rounded 
tooth is clearly to be seen. Our fig. H shows a smaller 
form of the penultimate stage, which would probably 
moult into the smaller limb (G). Mrs. Sexton, of the 
Marine Laboratory, Plymouth (who has given much 
time and attention to this species, and to whom I am 
indebted for valuable assistance in this matter), has 
* Trans. L’pool. Biol. Soc., Vol. IX, 1895, pp. 313, 305. 
