2 Prof. J. C. Schiédte on the Structure of 
tion of the organs of the mouth in masticating Condylopoda, 
founded on careful consideration of their anatomic connexion 
with one another, and, on the other hand, a definition of the 
morphological equivalents of all the different parts which 
shall prove its own correctness by its self-consistency. With 
less preparation than this it would be useless to attempt an 
“pein gai of the structure of the mouth in sucking Condy- 
opoda. 
Tt is one of the imperishable merits of Savigny that he has 
solved this problem in all essential points with regard to 
Insects ; but with regard to Crustacea almost everything still 
remains to be done. In this class the investigation becomes 
complicated by the circumstance that the body is more or less 
united with the head, so that a varying number of its foremost 
pairs of limbs may be assimilated to the organs of the 
mouth in point of form and use. It will therefore be advan- 
tageous to begin our investigation with the order of Isopoda. 
On the one hand, this order occupies one of the highest ste 
to which the class of Crustacea upon the whole attains in the 
scale of development of the articulate type, whereby the com- 
parison with the mouth of insects is much facilitated; whilst, 
on the other hand, it descends so low as to contain numerous 
parasitic species, and, therefore, is more likely than any other 
order to supply the key for the interpretation of the mouth in 
sucking Copepoda. How far this latter expectation will prove 
true cannot be shown more explicitly in this first paper; 
but the initiated will no doubt at once discern the application 
of the present analysis to lower forms. 
2. Although it is sufficiently well known that at least some 
Cymothoze live upon liquid food, and although Rondelet, more 
than three centuries ago, has said, concerning one of these para- 
sites, that it sucks like a leech*, the question of the structure of 
their sucking-apparatus is nevertheless, in a scientific point of 
view, entirely virgin soil. It is true that Bose believed that 
he observed in a Cymothoa a retractile sucker with a pair of 
small palpit; but Latreille declares that he could not find any 
such organ, and that he should consider it an anomaly in that 
* “Piscibus ita heeret, ut eripi non possit, sugit ut hirudo, nec prius 
abscedit, quam tabidum et exsuccum piscem reddiderit, reperitur cervici 
mugilum, luporum, et saxatilium piscium affixus.” (Libr. de Pisce. mar. 
Lugd. 1554, p. 576, “ De Pediculo marino.”) The woodcut at the head 
of Rondelet’s article on Pediculus marinus represents an <Anilocra, and 
approaches nearest to A. mediterranea, Leach. 
f Hist. Nat. des Crust. in Déterville’s small edition of Buffon, ii. 
. 208. The figure shows that the species on which Bosc has founded his 
escription of the genus was a Cymothoa sens. strict.; Briinnich’s “ Fiske- 
bjorn” (Entom. fig. 5), which he quotes, was more probably an Andloera. 
