542 General Notes. 
fishes, made by S. A. Forbes, and forming Article VII. of Vol. 
III. of the Bull Ill. State Lab. of Nat. Hist., eighty-three per cent of 
the food of the burbot consists of fishes, while Esox lucius takes 
ninety-nine per cent. of fishy food. Dorosoma feeds chiefly on 
fine mud containing about twenty per cent. of vegetable debris; 
the golden shad principally on fish; and the Catostomide, fifteen 
species of which occur in Illinois, consume molluscs and insects 
almost in equal ratio. The stone roller (Hypentelium), which in 
its habits simulates the Etheostomatide, feeds, like the members of 
that family, almost solely upon the larve of aquatic insects. The 
cat-fishes are nearly omnivorous, and are the only habitual scaven- 
gers among the common fishes of Illinois. Amia seems to feed 
upon Crustacea, fishes, and molluses, with very little mixture of 
insect food ; the gars entirely on fishes; and the singular Polyo- 
don chiefly upon minute insects and crustaceans, especially the 
former. Professor Forbes thinks it probable that Polyodon employs 
its paddle-like snout to stir up the weeds as it advances along 
the muddy bottom, thus driving the animal forms within reach 
of its branchial strainer, while the mud and vegetation have time 
to settle. : 
Though in the deep-sea fish-fauna no distinct bathymetrical 
zones, characterized by peculiar forms, can, according to the 
“Report on the Scientific Results of the Voyage of H. M. §. 
Challenger,” be defined, the abundance of fish-life decreases with 
the depth, as is shown by the number of species (232) found 
between 100 and 300 fathoms, as compared with 142 between 300 
and 500 fathoms, 7 between 500 and 700, 56 between 700 anc 
1500, 24 between 1500 and 2000, and 23 below 2000 fathoms. 
Partially grown examples of several species of freshwater 
` fishes have recently been successfully introduced into Chili 
from France. The principles followed in arranging the methods 
for this long transport, involving five changes previous 
accommodation of the water-cylinders on the steamer Sarata, were 
as follows: (1) The preservation of the same water. (2) Absence 
of alimentation. (8) Refrigeration. (4) Continual circulation of 
air. One hundred California salmon, about twelve centimetres long, 
forty carp of fifteen cent., twenty tench of twelve cm, sixty eels o 
thirty em, twenty barbels, and some burbots, minnows, etc., iepr 
the consignment; out of which thirty-nine salmon, toget er with 
the tench, carp and eels, arrived safely. Many of the other species 
died 
ied. 
Dr. J. Brock (Zeit. für Wissen, Zool., 1887), describes a ingat 
appendage present immediately behind the anus in the Siluro : 
genus Plotosus. The apparatus in question consists of a reg” 
bunch of small bladders of cavernous, and therefore, proba y a 
erectile nature. The fishes of this genus ,are mu ae 
account of the terrible and often fatal wounds caused by t | 
fin spines. 
