10 Prof. J. C. Schiodte on the Structure of 



and to distend gradually the piece which lies between them, 

 until it is cut through by the cutting edges which glide clipping 

 past each other. In harmony with this structure of the mouth 

 IS the slender form of the body, the thin antennae, and the well- 

 developed swimming-feet ; and it cannot be doubted, therefore, 

 that Cirolana3 are purely carnivorous. The testimony of dif- 

 ferent authors goes in the same direction. Thus we find in 

 Strom's physical and topographical description of the district 

 of Sondmor, in Norway, a description of a " Fish -Bear," which 

 must be a Girolana {G. horealis in allprobabihty), and which^ 

 he says, " creeps into the fishes through the anus and eats the 

 flesh of the fish from the inside, so that, if it only has time, 

 it may eat the whole of the fish." The author of this paper 

 asked Professor Kroyer, the celebrated and experienced con- 

 noisseur of Crustacea and Fishes, whether he remembered any 

 fact confirming the conclusions as to the mode of living of Ciro- 

 lanse which are suggested by the structure of their mouth ; and 

 Professor Kroyer then related that once, near the shores of Nor- 

 way, not far from Throndlijem, he caught a large codfish which 

 teemed Avith Girolana horealis. The latter had eaten out such 

 large cavities in the flesh that there was little left of the fish 

 except skin and bones. In the hurry to secm-e this rich harvest 

 Professor Kroyer tried to help himself by keeping some of the 

 parasites in his closed hand, but they bit him so ferociously 

 that he was obliged to let them go at once. 



8. The third type is that of Serolides,of which Serolis Orhig- 

 nyana, M.-E., may serve as an example. The stem of the 

 mandibles (fig. 2,7n) forms a very large, flat, oblique, quadrangle 

 placed in a slanting position, and is evidently almost exclu- 

 sively destined to give room for the insertion of the flexors, as 

 the palpus rises from the exterior and posterior corners. The 

 outer lobe has a similar shaj)e, but is somewhat pinched ofl" from 

 the stem in the place where the large labrum begins to cover 

 it in front ; there is no grinder, and the prehensile joart is thick 

 and slightly spoon-shaped, the apex broadly truncate, with 

 thick rounded edge ; the inner margins of the mandibular lobes 

 on the right and left sides meet each other accurately, but do 

 not cross so as to cover each other. The inner lobe is small, 

 divided into two lobules, which are attached to the outer lobe 

 close under its prehensile part. On the right mandible both 

 lobules are very small, soft, bipartite ; but on the left mandible 

 the foremost lobule is much increased in size, thickly chitinized, 

 and resembles the prehensile part of the outer lobe by its clumsy, 

 rounded transverse edge. The mandibular palpus is long, 

 slender, the two first joints fitting into a shallow groove run- 

 ning along the outer margin of the stem and continued between 



