1884. | Zoblogy. 549 
three years at Roscoff in observations and experiments upon the 
subject, more wonderful than has been hitherto believed. The 
nauplius, after four days and five months, transforms into a cypris, 
which refuses for three days to fix itself. Then, always during 
darkness, it attaches itself to young crabs from two to twelve 
millimeters in width, seizing a hair of the crab with its prehensile 
antennz. It may become fixed to any part, but prefers the back 
of the tail or the base of the legs, never the ventral face of the 
abdomen. As soon as it is fixed, it is transformed by a molt 
into a sort of lengthened sac, suspended by its antennz, and with- 
out limbs. This sac secretes at its antennal pole a hollow dart, 
ending below in a funnel opening into the cavity of the sac, and 
above ina very sharp point. This dart passes through the cavity 
of the antennz that has seized the hair, and pierces the teguments 
ofthe crab at the soft ring at the base of the hair. The contents 
of the sac then commence to enter the funnel end of the hollow 
dart, and pass gradually into the tissues of the victim. The con- 
tents of the sac consist of cellules, of which the superficial ones 
"present the cellular skin of the larva, while the central ones are 
*sort of nucleus which existed in the nauplius and cypris, and 
 nstitutes the genital organs. When the Sacculina has thus 
Moculated itself into the body of the crab, it travels to the ab- 
dominal region, and the genital nucleus pierces its envelope and 
s ents of its host, and appears upon the outside of the 
skin Thus the portion of the parasite in the body represents the 
l of the larva. The name of Rhizocephalus is therefore inex- 
origa M. Delage proposes for the group the name Kentrogo- 
~» and considers them very different from either Lerneans or 
The parasite does not fix itself to the zoéa, nor to 
passed a certain age. Among the Crustacea 
Were th, the French expedition to Cape Horn, the most common 
f € large spiny Lithodes antarctica; another, Lithodes (L. 
| long limbs with shorter limbs; a Eurypodius, with extraordinarily 
_ and more z a small Halicarcinus, with a flattened body; a Galatea, 
-which rarely some shrimps and isopods, among the latter of 
Q genus Serolis was most common. 
states thar ; M. Ralph S. Tarr, in a communication to Science, 
Species ~ata Wales, Mr, Ch de Vis described the following new 
PYON of fishes from New Britain and the adjoining islands: 
= berguttatus and cruentus, Mesoprion flavirosea, Tetraroge 
