THE NORTHERN RIBBON-FISH. 11 
front of the succeeding pharyngo-branchials; the cartilaginous continuation or 
epiphysis, which Parker describes in Regalecus under the name of para-branchial, 
is not to be detected. 
In the three succeeding arches the cerato-branchials call for no remark. The 
hypo-branchial in the second arch resembles that of the first, but is much smaller ; 
in the third, the hypo-branchials are thrust forwards, and appear as free projecting 
points of bone, attached posteriorly to a mass of cartilage, close to, but below the 
copula, which receives the corresponding cerato-branchials ; in the fourth arch, the 
hypo-branchials are represented only by minute rudiments. The epi-branchial is, in 
the second arch, a short rod, on which a small projection is noticeable posteriorly ; 
in the third and fourth arches, the epi-branchials are forked above, the anterior limb 
of the fork being the articular process for the pharyngo-branchial, the posterior 
limbs being applied to one another and united by ligament. The pharyngo- 
branchials are of peculiar form. The two which belong to the second and third 
arches are long bones, broad posteriorly, at which end they bear several: sharp, 
curved teeth, and narrow anteriorly, where they are attached in common to a 
pointed cartilagmous epiphysis. Each is rounded above and grooved below, and 
articulates by a tubercle below with the corresponding epi-branchial. The fourth 
pharyngo-branchial also bears teeth, but is a shorter and relatively broader bone. 
The teeth on these three pharyngo-branchials are four, five, and six in number 
respectively. The fifth arch consists of a pair of long and very slender cerato- 
branchials, tipped at each end with cartilage. 
The copule or median elements are very numerous. The first of these (b.hy.) 
the basi-hyal or glosso-hyal, is cartilaginous, and forms the supporting skeleton of 
the short, blunt tongue. The second (b.br.') is large, well ossified, and produced 
into a deep keel below. It answers to W. K. Parker's first basi-branchial. 
Behind this we have—third, a cartilaginous inter-space, to which is attached the 
first branchial arch; a small centre of ossification is present in it. Fourth, a 
distinct ossified element (b.br.”), flat and sculptured above and grooved below—the 
second basi-branchial. Fifth, a cartilage attaching the second arch: two small 
centres of ossifications are present in it, side-by-side. Sixth, a long, rod-like, 
rounded bone (b.b7*.), slightly narrowed in the middle—the third basi-branchial. 
Seventh, a cartilage with one nodule of ossification ; just below this, the cartilage 
uniting the hypo-branchials and cerato-branchials of the third arch meet in the 
middle line. Eighth, a cartilaginous element, with an irregular centre of ossifica- 
tion (b.br*.). The two cartilages representing the hypo-branchials of the fourth 
arch, each with a nodulary ossification, meet below b.br*. Ninth, a small, but long 
and thin, laterally compressed cartilage (b.br°.), devoid of ossification. Succeeding 
this are two round nodules of cartilage belonging to the fifth arch. 
It is perfectly clear from this description that, as T. J. PARKER has pointed out 
in Regalecus, the median elements known, and described above, as basi-branchials, 
