202 THE ZOOLOGIST. 
in others. This pad is firmly attached during life, as it takes 
the thrust of the lower pharyngeal teeth in chewing, but after 
death it is easily detached, leaving the lining membrane of the 
mouth seemingly intact. The pad varies very much in size, 
thickness, and shape in the different species, in some being a 
fairly solid lump, as in Cyprinus carpio; in others, a thin but 
hard striated cartilage, as in Cirrhina mirgala. 
Cyprinus carpio. The Carp. Fig. I., 1. 
This fish has a number of soft gill-rakers that fit into each 

Fie. I. 
1. Cyprinus carpio; gill-rakers. 2. Callous pad of the same fish. 3. Pharyn- 
geal teeth of another C. carpio, and spare tooth. 4. Part of base of skull. 
5. Callous pad that fits on same. Food passes through to the teeth in the 
direction away from the reader. 
other from alternate sides and form a very complete filter; in 
general appearance each gill-arch looks like a frond of a fern. 
There are eighteen gill-rakers on the first cerato-hypobranchial 
arch, with eight on the epibranchial ; the inner sides look at 
first sight as if denticulated, but this is due to a number of soft 
papille. The lower pharyngeal teeth are far back, and can 
with difficulty be seen when looking into the gullet, but can 
readily be felt by inserting a finger. The teeth are molariform, 
