1883.] Zoology. 1075 
be superfluous to discuss in detail his objections to Gaule’s views. 
—Journ. Royal Microscopical Society, Fune. 
EXTERNAL PARASITE OF THE Trout.—L. F. Henneguy de- 
scribes, in the Comptes Rendus of the French Academy, an ani- 
malcule which covers the surface of young trout. When fixed, 
these infusoriform parasites have the appearance of small pyri- 
form cells, fixed by their narrower end. When the infusorian is 
free it expands and has the form of a Haliotis shell. If the fish 
dies the infusorian guest abandons it and disappears, probably to 
take up its abode on another. Most nearly allied to Bodo 
(Amphimonas ) caudatus, it is distinguished by having three in- 
stead of two flagella; the new form may be called B. necator, 
This, says the notice in the Journal of the Royal Microscopicat 
iety, appears to be the first described external parasitic flagel- 
late infusorian. It seems to cause the death of its host by giving 
rise to an alteration in the activity of the cells of the epithelium; 
or in a young trout the cells appear to be undergoing active 
division, which ceases when it becomes attacked by this parasite. 
New Porto Rico Lann SHetis.—Cistula consepta and Chon- 
dropoma tortolense Pfr., var. major, are described by Professor E. 
von Martens, from Porto Rico. Thos. Bland appends a note 
(Annals N. Y. Acad. of Sci., pp. 370- 371).—A. F. Gray. 
MOLTING oF THE APoDEMES IN CRUSTACEA F, Macquard, 
attracted by the recent statement of Vitzen that the apodemes, 
with some other parts, preserve their ordinary relations on the 
ecdysis of the lobster, notes that he has observed in the exuvia- 
tion of the spiny lobster that the arcades formed by the meso- 
phragms, and the longitudinal branches connected with them, are 
broken just as much as are also the endothoracic arcades and the 
Paraphragmal pieces of the endosternites. In other words, all 
the connections between the mesophragms of the two sides, or of 
uction is prepared for by a decalcification and softening of 
these parts, 
In the lobster, where the arrangements are a little different, we 
li likewise a division of the mesophragms along the middle 
fea’ and the separation of the branches of the endopleurites 
om those of the endosternites, Similar solutions of continuity 
rd Probably be detected in the apodemes of the Brachyura.— 
ourn. Roy. Micr. Society. 
pe loLTING OF THE SHELL IN LimuLus.—The mode of molting of 
a crust or shell of the king or horseshoe crab (Limulus) iok 
with ‘lieve, never been described, although we have been familiar 
“tit for a number of years ; in fact, any boy who has been 
ught up along the shores of our bays and estuaries from. 
