A PROTRACTED SEARCH 399 
examining twelve specimens of Mysis oculata he found six 
infested with young Dajus mysidis. On the other hand, 
at the Neapolitan Marine Station, Salvatore lo Bianco 
had opened about 10,000 Brachyura before he came across 
a couple of Risso’s Ergqyne cervicornis, and MM. Giard and 
Bonnier themselves had to sacrifice tens of thousands to 
provide the requisite materials for their ‘Contributions a 
étude des Bopyriens.’ 
Should any sensitive persons regret this expenditure 
of life on a scientific investigation, they must remember 
that it is perfectly trivial compared with what is continu- 
ally being exacted for the meaner purpose of tickling man’s 
palate, trivial also compared with the havoc so frequently 
wrought by storms among creatures of this same class, and 
further, that against every crustacean destroyed must be 
set the lives of many others preserved which would else 
have been its victims. 
According to the authors cited only Portunion Koss- 
manni on Platyonichus latipes can be called common. They 
opened an-enormous number of Porcellana longicornis at 
ever so many points of the French coast before meeting 
with a specimen of Kntoniscus Miilleri at Concarneau. 
Both there and at three other places they examined the 
Pagurid Clibanarius misanthropus without finding a para- 
site, although at Mahon in Minorca Dr. Fraisse found upon 
this crustacean a Peltogaster, a Cryptoniscus, an Athelque, 
and a Palevyge. Thousands of Portunus depurator (Linn.) 
and Porcellana platycheles had in like manner yielded them 
no parasites. ‘They feel ready to affirm that our common 
edible shrimp, Crangon vulgaris, is free from Bopyrids, 
though they remind us that Crangon munitus, its American 
congener, is infested by Argeia. ‘The occurrence of Epica- 
ridea may be called, in terms of our present knowledge, 
very capricious. It not unfrequently happens that, where 
they occur at all, they occur in some profusion, their hosts 
suffering as it were from an epidemic attack. One host 
may undoubtedly carry several species of parasite, but it is 
an axiom with Giard and Bonnier that both among the 
Epicevidea and the Rhizocephala no species of parasite has 
29 ; 
