of Edinburgh^ Session 1865-66. 
657 
(2.) Internal Structure of Galomoichtliys Calabaricus (J. A. 
Smith.) Bj K. H. Traquair, M.D., Demonstrator of 
Anatomy in the University of Edinburgh. 
On dissecting those specimens of Galamoichtliys^ entrusted to the 
author by Dr Smith, the greatest similarity was found to exist 
between their internal organisation and that of Polypterus ; the 
chief differences being dependent on the great elongation of the 
body of the former fish, while the abdominal cavity extends propor- 
tionately still further back towards the caudal extremity than is the 
case even in the genus last mentioned. 
The vertebrae resemble in construction exactly those of Polyp- 
terus, but are very much increased in number, amounting, in the 
specimen which was used for the preparation of the skeleton, to 
110, the first of which has no body, consisting merely of neura- 
pophyses, spinous process, and a pair of ribs. These latter form 
the first of the series of well- developed upper ribs, which extend 
in the horizontal intermuscular septum, as far back as the ninety- 
eighth vertebra. But the lower series of ribs are very deficient in 
development in comparison with those in Polypterus, where the 
whole series of abdominal vertebree, except the first, is furnished 
with those appendages, which posteriorly attain a considerable 
length. In Galamoichthys^ on the other hand, those lower ribs are 
very minute, and no trace of them was found in advance of the 
sixtieth vertebra. The number of abdominal vertebrae is, in the 
specimen alluded to, 100, of caudal, 10 ; showing the very great 
proportional elongation of the abdominal and shortening of the 
caudal region. The vertebral column projects beyond the last 
caudal vertebra, as a notochordal continuation or ‘‘ Urostyle,” con- 
cealed among the rays of the caudal fin. The bones supporting 
the fins agree in their general conformation with those in Polypterus, 
— there being, however, a less ossified state of the radius, ulna, 
and carpus, while the pelvic bones, along with the ventral fins, are 
completely absent. The first dorsal finlet is placed opposite the 
forty-ninth vertebra. 
As regards the form and arrangement of the bones of the cranium 
and face, the most complete correspondence is found with those of 
Polypterus^ a space being found, however, below the preoperculum, 
which, in various species of Polypterus^ is defended by a variable 
