76 
The Port Elizabeth specimen has eight teeth on the rostral 
crest and is abnormal in having only two on the lower edge, 
the foremost just under the foremost of the upper teeth, and 
the penultimate a little in advance of the penultimate upper 
tooth. In the Durban Museum specimen the upper teeth are 
only six in number, a seventh, the foremost, being represented 
only by a depression of the margin. The three lower teeth are 
all in advance of the foremost of the fully-developed upper 
teeth. Bate says of these lower teeth, “‘ According to de Haan’s 
figure they are situated, or at least two of them, posterior to 
the most anterior tooth on the upper margin, whereas in our 
specimens of Penaeus monodon, they are all in advance of that 
position.” It is true that in de Haan’s figure only one of the 
lower teeth is in advance of the foremost upper one, but in 
Bate’s own figure the case is almost exactly the same, only 
that the foremost upper tooth being poorly developed, the 
middle lower tooth is a little in advance of it instead of a little 
behind. It is tolerably certain that considerable variation 
occurs in these details. The apex of the rostrum admits of 
some upward curvature, whereas Bate describes the whole 
rostrum as straight. In his figure also the two flagella of the 
first antennae are not nearly as long as the peduncle, so far 
making an approach to the proportion which Dana gives for 
his P. carinatus. Our specimens, on the contrary, agree with 
the account above quoted from de Man. 
Since nothing is said by Fabricius about those particular 
features in regard to which a distinction has been drawn be- 
tween his species and those above named by de Haan and 
Dana, it is certainly a matter of some convenience that all the 
three supposed species should now be accepted as one and the 
same. 
Along with the female specimen from Zwartskop River 
already discussed, was obtained a male of just the same size 
and general appearance; but in this the teeth on the rostral 
crest are only seven in number, while on the lower margin 
there are four, three of them in advance of the foremost upper 
tooth, and the fourth only slightly behind it. 
Kishinouye identifies P. semisulcatus, de.Haan, with P. 
monodon, Fabricius, and in our specimens the thelycum of the 
female and the petasma of the male agree very well with the 
figures of those parts as drawn by Kishinouye for P. monodon. 
On the other hand, Miss Rathbun, in commenting on P. 
ashiaka, Kishinouye, says, “This species is very near P. 
semisulcatus, de Haan (not = P. monodon Fabricius, Kishi- 
nouye).” 
