TRANSACTIONS OF SECTION D. 421 
from subopercle, only its anterior end visible from without. The prominent 
rostrum (much shortened in females of P. draconis and P. volans) is formed by 
the coalesced nasals. Pterygo-palatine bar very shortened, consisting of the 
palatine and only one pterygoid (ento- and metapterygoid wanting), completely 
separated from hyomandibular suspensorium and connected with anterior end 
of vomer; together with premaxilla and maxilla lodged in a precranial cavity 
below the base of the rostrum. Between premaxilla and maxilla is interpolated 
a large separate bone, corresponding to a small cartilaginous disc or meniscus 
found in other fishes. Front part of maxilla forming a large process projecting 
over premaxilla into anterior part of the subrostral chamber. Mandibular 
suspensorium consisting only of hyomandibular, symplectic and quadrate.— 
Branchiostegals 5, well developed (hitherto only one observed and described as 
rudimentary). Basibranchials 2; lower and upper pharyngeals with conical 
teeth. Hypobranchials I.-l1II. present; epibranchial IV. very long and stout, 
widely separated from its ceratobranchial. Pharyngobranchials II. and III. 
fused into a well-developed dentiferous plate; pharyngobranchials I. and IV. 
absent. 
Clavicular arch consisting only of post temporal and clavicle; part of the 
latter enters the dermal skeleton of the trunk. Scapular arch and pectoral fin 
almost horizontal, their inner faces looking upwards. Foramen scapulare 
bounded by both scapula and coracoid; the latter with processes fastened to the 
ventral carapace. Articular face for pectoral rays fixed across a slit in the 
carapace and made up of part of the scapula and three stout basals. 
Pectoral rays unbranched, but fundamentally like soft rays; they are jointed 
distally, stiff basally, and composed of two longitudinal parts; but owing to the 
horizontal position of the fin the otherwise lateral constituents in Pegasus are 
upper and lower, and instead of being equal halves, the upper is much more 
slender than the lower. In the so-called pectoral spines of P. draconis and P. 
volans the upper constituent is almost thread-like, imbedded in a furrow along 
the lower one, which may be extremely stout (cf. especially the 5th pectoral ray 
of P. volans) ; the original jointed condition is much obscured but always obser- 
vable, and the extreme apex is always soft and distinctly jointed. 
Pelvis large (to a certain degree resembling that of Sebastes), by means of 
short ligaments fastened to the clavicles. First ray of ventral fin a well- 
developed, true spinous ray (hitherto completely overlooked); one or two 
elongated, unbranched soft rays and a slender short one (Pegasus draconis, P. 
volans, P. natans : +2, P. lancifer 1+3).—Abdominal vertebre 7; the anterior 
6 immovably joined, devoid of ribs, provided with large spinous processes 
forming together a long partition, the upper margin of which (from vertebra 
2 to 6) carries a modified interneural, probably representing an aborted first 
dorsal fin. 7th vertebra movable, provided like the 8th (the first caudal) with 
strong ribs (probably ‘ epipleurals’ rather than true ribs). Number of caudal 
vertebre: P. draconis 12, P. volans 13, P. natans 15.’ .Vertebre 8-12 con- 
nected with 5 dorsal and 5 anal interspinous bones, all bisegmented; first 
and interspinous bone considerably enlarged. Last caudal vertebra terminat- 
ing as a vertical plate (probably the urostyle fused with 2 hypurals), 8 caudal, 
5 anal, and 5 dorsal soft, unbranched rays. 
The main longitudinal muscles of the trunk have been modified under the 
influence of the immovable carapace. The dorsal and ventral portions are 
separated on each side by a considerable interspace, the lateral body wall con- 
sisting only of the dermal armour and its peritoneal lining; besides the anterior, 
part of the dorsal portion is mainly reduced to a flat thin ligament. In the 
posterior part of the trunk and in the movable tail the longitudinal muscles are 
well developed, with strong tendons inserted to the dermal skeleton as well as 
to the vertebre.—Gills four, each a double row of Jeaves. Pseudobranchia large, 
with 6-7 leaves.—Glill-rakers small, papilliform; a slit in front of lower 
pharyngeal.—Air-bladder absent. The greater part of the contents of the body 
cavity lodged in front of pelvis. A large left and a small right lobe of the 
liver are connected by a narrow bridge below the alimentary canal; most of the 
lobes situated dorsally to the latter. ‘The wide awsophagus passes into the quite 
straight and simple stomach, which again without any demarcation continues 
' P. lancifer I have uot had the opportunity to dissect, 
