On the Conservation of Species in Parasitic Crustacea. 271 
rugose-punctate, transversely impressed near the base; centre 
of disk with a longitudinal groove. Elytra broader than the 
thorax, oblong, sides narrowly margined, their outer edge, to- 
gether with the apical border, serrate; apex rounded; above 
convex ; each elytron with eight rows of deep regular punctures, 
interstices obsoletely costate. : 
A single specimen, without locality, in my own collection. 
Microrhopala Sallét, n. sp. 
M. anguste ovata nigra; thoracis vittis duabus elytrorumque vitta 
lata humerali, a basi fere ad medium producta, postice angustata, 
fulvis ; elytris profunde punctato-striatis, interspatiis alternis ob- 
solete vittatis. 
Long. 2 lin. 
Hab. Guatemala, Mexico. 
Thorax transversely excavated at the base, deeply punctured, 
a longitudinal fulvous stripe on either side, just within the 
lateral border, continuous with the humeral patch on the elytra ; 
sides of the elytra subparallel, scarcely oval, finely toothed. 
In my own cabinet; also sent me for examination by M, 
Sallé and Rev. H. Clark. 
[To be continued. } 
XXXII.—On the remarkable Means by which certain Species of 
Parasitic Crustacea effect their Conservation. By M. Kucine 
Hesse*. 
Tue object of my present paper is to call attention to the means 
by which the conservation of their species is assured to certain 
parasitic Crustacea, such as the Trebie, the Caligi, the Pandore, 
and the Chondracanthi. 
All carcinologists are aware that many of these singular ani- 
mals, which, on their issuing from the egg, are furnished with 
powerful instruments of locomotion, are, on the contrary, very 
insufficiently provided with them when in the adult state, some 
being even completely deprived of them ; that, moreover, there 
are some to which organs of vision have been denied, sometimes 
in the males, sometimes in the females; so that these dis- 
inherited creatures become perforce stationary, and are com- 
pelled to follow the fortunes of the fishes at whose expense they 
live. 
In this situation, so perilous to the species, it is easily con- 
* Translated by W. S. Dallas, I'.L.S., from a separate impression, com- 
municated by the author, of his paper in the ‘Mémoires des Savants 
trangers.’ 
