280 
Nevertheless a step like that is not justifiable for the present. 
A study of the many specific descriptions of the literature, and 
the curious faet that also in the present material several „nova 
species* 4 , and only two previously described ones could be pointed 
out, are apt to awake suspicion as to the base of the specific 
systematic of the genus. No doubt several of the species shall 
have to disappear, on account of deficient description; I shall here 
f. inst. point to Alepas tubulosa Quoy et Gaimard of the in- 
vestigated waters; it cannot be reidentified, and the name should 
be dropped. It is rather possible that the named species might be 
identical with some of the species described as new below; but 
only a reexamination of the type specimen will enable us to settie 
the identity, the external shape being of no use whatever in this 
case. 
On the other hånd, a thorough revision of each character used 
as specific distinetion in this genus, based on the previously de¬ 
scribed animals as well as on an extensive new material, is greatly 
desirable, and we must await such a revision before we can hope 
to get a solution to many questions concerning this intricate genus. 
Among the characters not mentioned by Pilsbry (1907) nor 
by Annandale (1909) I wish to call the attention to some, which 
seem to be of interest. In the Heteralepas- group, as far as can be 
seen from the literature, the filamentary appendage at the base of 
cirrus I is small, whereas in Paralepas on the contrary it is well 
developed and obvious. Even more interesting are the maxillae. 
Owing to their conservatism in general among the cirripeds, 
we must ascribe to the mouth feet a great phylogenetic interest. 
Now, in Heteralepas s. str. a great exeavation, generally comprising 
almost one half of the cutting edge, below the upper spine, seems 
to be found in every species. In Paralepas this exeavation is re- 
duced to a small, many times even rudimentary notch, and the 
cutting edge is here often all but entire. On the other hånd, Para¬ 
lepas tends to develop two main spines at the middle thirds of the 
cutting edge, and these spines often attain the same size as the 
upper spine, and strongly dominate in the row of bristles. This 
character is not found in Heteralepas s. str. We can moreover see, 
that the maxillae of the genus are of the same construction as in 
Poecilasma-Octolasmis, and totally di ffer from those of Conchoderma- 
