شد ee PME s‏ سس سر 
58 MR. A. HANCOCK AND THE REV. A. M. NORMAN 
Chondraeanthide. In comparing the genus Chondracanthus with Splanchnotrophus, we 
see this relationship in the structure of the antenne, the first pair in both being formed 
of few joints, the second pair in both assuming the form of strong prehensile hooks. It 
is, however, in the oral apparatus that this connexion is most evident. Both genera are 
provided with a largely developed labrum, which overhangs the oral orifice and mandi- 
bles, and is apparently capable, both in the one and the other, of encircling these latter 
organs within a sort of short imperfect suctorial tube or disk. In both, too, we observe 
the same peculiar rudimentary condition of the maxille ; while the two pairs of foot-jaws 
have much in common: they are closely approximate to the mouth in each; but the 
second in the female of Chondracanthus are large, and have a transverse direction, instead 
of being directed forwards side by side as in Splanchnotrophus; it is satisfactory, how- 
ever, to find that in the male of the former genus the second pair of foot-jaws areno larger 
than the first, and assume a longitudinal position between them and the maxille, exactly 
as is the case in the new forms described. 
The connexion of Splanchnotrophus with Chondracanthus is likewise seen in the peculiar 
lateral appendages of the former. The remarkable conformation of these structures, 
together with the fact that they are used as clasping-members with which the animal 
enwraps the viscera on which it feeds, might lead the observer to entertain the impres- 
sion that they were the homologues of thoracic feet. This, however, is not the case: 
they arise from the sides, not from the front, of the thorax, and are clearly digitiform 
processes of that division of the body, similar to those we find to exist in Chondracanthus ; 
for the thorax of this latter genus is furnished in front with two pairs of organs, which 
are transformed thoracie feet, and these are homologues of the two pairs of feet we have 
described as existing in Splanchnotrophus, but, in addition to these two pairs of feet, 
the sides are produced into more or less numerous lobular or digitiform appendages 
homologous with the three pairs of simple arm-like processes in our new genus. This is 
evident from the general resemblance of the parts, and by the fact that in both cases por- 
tions of the ovaries are pushed into them. They are thus of a similar nature also to the 
lateral wing-like expansions of Nicothoé, within which portions of the ovaries are also 
placed; and in Nicothoé these expansions cannot be homologous with the thoracic feet, 
because the full number of these limbs is present in the usual form. Moreover, in 
Splanchnotrophus it is quite impossible for these processes to form part of a series with 
the thoracic feet, whether or not the latter are the first and second pairs. Indeed, the 
anterior and posterior lateral processes are respectively in the same transverse line with 
the two pairs of thoracic feet, and consequently they must be members of the same seg- 
ments to which the feet belong. If therefore those organs which we have called thoracic 
feet be really so (and of this there can scarcely be a doubt), then the lateral arm-like 
appendages cannot represent them, and the conclusion is forced upon us that they are 
merely thoracic processes. 
عام‎ co a es the close relationship existing between Splanchnotrophus and Chon- 
deg ui ou M look at the males of the two forms. In both genera 
eaphabithdeiti e m general appearance resemble each other, having the anterior 
Ic segment large, and the rest of the body attenuated and produced. 
