LOPIIOBRANCHS. 
661 
PHYSOCLYSTI LOPHOBRANCHIT*. 
Physoclysts with tufted branchial laminae. 
This single character is enough to divide from the 
rest of the Physoclysts a series extremely remarkable 
in many respects, which contains two families, and of 
which our Pipefishes and the Sea-horses of warmer re- 
gions are well-known types. 
The gills of the Teleosts generally consist, as is 
well known, of a great number of branchial I a mi me — 
on the first branchial arch of a Cod 3 dm. Iona:, for 
example, we can count about 100 pairs — which are 
arranged in a double row on the outside (the convex 
side) of each branchial arch, like the teeth of a comb 
but in pairs, each lamina alternating with (obliquely 
opposite) the other lamina of the pair, though they are 
united to each other for a greater or less distance from 
the base. Each of these laminae (fig. 1 66) is furnished 
on each side (above and below) with numerous, trans- 
versely-set lamellae — in the Cod we can count as many 
as 1,000, but in other Teleosts they are much fewer, in 
the Gudgeon ( Gobio fluviatilis) for example, only 50 or 
60 — which are honeycombed by the capillary network of 
the respiratory vessels with a view to the oxygenation of 
the blood and its transmission from the branchial arteries 
to the branchial veins. In the Lophobranchs the num- 
ber of the branchial land me is considerably reduced, in a 
Pipefish, for example, being only 5 — 8 pairs on each 
arch, the minimum number on the foremost and hindmost 
of the four branchial arches, the maximum on the two 
middle arches. But to compensate for this the com- 
paratively few branchial lamella: are considerably en- 
larged, being visible even to the naked eye, or at least 
with the help of a weak magnifying-glass. They are 
largest at the middle of each lamina, their size decreas- 
ing regularly towards the base and the tip thereof; and 
the lamina itself is curved, not unlike a peacock’s feather. 
“By means of this arrangement,” says Retzius, “the 
branchial laminae (fig. 167) acquire an appearance some- 
thing like that of bunches of peacocks’ feathers, set 
alternately and touching each other with the convex 
part of their curves. When we see the two rows of 
these bunches from without (fig. 168), the figure also 
reminds us somewhat of the foliation of Salvinia .” 
Fig. 166. A pair of branchial lamina? attached to a section of a 
branchial arch in the Cod. b, the lamella?. Magnified and schema- 
'* tized. After Tit. Williams. 
Fig. 167. A pair of branchial laminae attached to a section of a 
branchial arch in Syngnathus. Magnified. After A. Retzius. 
Fig. 168. A branchial arch with its alternating lamina? and their 
lamellae in Syngnathus. Magnified. After A. Retzius. 
L’ordre des Lophohranches, Cuv., Regne Anim., ed. I, tom. II, p. 155. 
