116 Dr. R. H. Traquair on the Anatomy of Calamoichthys. 
arteriosus, which is furnished internally with numerous valves, of 
unequal size. The branchial artery gives off first a large lateral 
branch on each side, which divides into three for the three pos- 
terior gills; the trunk then bifurcates, giving off a branch for 
the anterior gill of each side. As in Polypterus, the posterior 
gill has only one row of leaflets, and the cleft behind it is want- 
ing. No trace of a ‘‘pseudobranchia” was found, an organ 
likewise absent in Polypterus. The spleen is very long and 
slender, lying closely along the great air-bladder. The air- 
bladders are two in number, opening by a common orifice into 
the lower aspect of the throat, behind the gill-clefts. That of 
the left side is small, being only 22 inches in length in a fish 
of 10 inches; it is closely adherent to the side of the cesophagus 
and commencement of the stomach. That of the other side 
measures 8? inches in the same fish, and extends through the 
whole length of the abdominal cavity, lying closely along the 
under surface of the vertebral column. 
Like the rest of the abdominal organs in general, the kidneys 
are very slender and elongated ; each consists of a number of little 
lobules, which lie in the concavities on the under surfaces of the 
vertebral bodies. The excretory duct or ureter lies along the 
outer border of the organ, and passes straight backwards to 
unite with the genital duct, and, with its fellow of the opposite 
side, at the urogenital pore. The ovaries and oviducts corre- 
spond exactly with Miiller’s description of these organs in Po- 
lypterus (Trans. Berlin Acad. 1844). Each ovary is in the form 
of a flattened plate, suspended in front of the posterior part of 
the kidney by a mesentery, is solid, and consists of a stroma 
imbedding ova of all sizes, up to 74; inch diameter. The ovi- 
duct, proceeding forwards from the urogenital pore as a pretty 
wide tube, crosses beneath the ovarian mesentery, and opens 
into the peritoneal cavity, on the outer side of the gland, and 
closely above its lower extremity. The ovaries are not sym- 
metrical in position, one being in advance of the other, so that 
also one oviduct is longer. In a female measuring 82 inches 
the right ovary was 14 inch in length, its anterior extremity 
being placed 43 inches from the top of the snout, and the length 
of the oviduct 1% inch, while the left measured 12 inch, was 
situated at its anterior extremity 53 inches from the tip of the 
suout, and had a duct of 1,3; inch. The testes are very mi- 
nute, and situated very far forwards, each being a small oval 
body ;8; inck in Jength in a male of 10 inches; and in the same 
specimen the right one was situated 24, and the left 244 inches 
back from the tip of the snout. A very minute duct runs back- 
wards parallel with and close to the ureter, which it joins near 
.the urogenital pore. 
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