174 
THREE-SPINEl) STICKLEBACK. 
satisfy the intention I have in view in the account of these 
fishes, hy giving a description, as -well as a figure, of each 
of the varieties as they have come within my observation; 
and my earnest thanks are due to Edmund T. Higgins, Esq., 
of Bristol, for the opportunity I have had of examining some 
examples of more than the usual size — giants of their race — 
which were obtained hy him from the neighbourhood of 
Liverpool, and selected from a multitude of others that shewed 
no difference from the more common examples obtained in 
other districts. 
Willoughby describes this fish as growing to the length of 
two inches and a quarter, and Sir. Jenyns to three inches. 
Sly largest example measured three inches and three fourths; 
its depth one inch. The body compressed, sloping circularly 
from the first spine to the mouth; under jaw longest, gape 
rather small, teeth conspicuous. From the upper jaw the 
head is covered with a cuirass, the border of which bends 
down at the sides on a line with the gill-covers; a separate 
plate with a blunt projection about the pectoral fins. The 
pectoral fins attached to a broad half-circular plate, and below 
this a plate which extends a rounded angle back towards the 
belly. On the ridge of the back are three plates, on the two 
hindmost of which are seated the two first free spines; a third 
and shorter spine is close to the origin of the dorsal fin. 
Four plates pass downward from these dorsal plates or shields, 
and two of them reach the ventral plates, one of which is 
broad, and covers the belly to the vent. It is bound down 
through the whole length, and a prominence or line runs 
