458 Prof. Reid on the Vogmarus Islandicus. 
7 ths of an inch, and the thickest part of the body where the 
viscera were placed measured only about 1 inch. The thickness 
of the most muscular part of the body immediately behind the 
gills and a little above the vertebral column, measured somewhat 
more than an inch. 
In this, as in the specimen of Trachypterus vogmarus described 
by Professor Reinhardt, the height of the sword-blade-shaped 
body was the same or nearly the same for more than one half of 
its length; while in the specimens of Trachypterus falx and 
T. iris described by Valenciennes, the greatest height of the 
body was at or near the occiput, from which it gradually tapered 
towards the tail. | 
The lateral line of the body at its commencement immediately 
behind the operculum was nearer the upper than the lower edge 
of the body, but it began immediately to descend, and continued 
its course backwards to the tail, running nearer the lower than 
the upper edge. The lateral line immediately behind the gills, 
where the height of the body was 8 inches, was placed 33 inches 
from the upper edge; and where the height of the body was 11 
inches, it was 43 inches from the lower edge. 
It was not easy to reckon exactly the number of the dorsal 
rays, but I counted 176. The length of the longest dorsal ray 
was 41 inches. Only six rays were left in the caudal fin, and 
the longest of these was 8} inches. There were ten rays in each 
pectoral fin, and seven of these were considerably longer than the 
other three. The longest were from the second to the seventh, 
reckoning from before backwards. The length of the pectoral 
fin was 21 inches and nearly 1 inch in breadth. 
A number of small cartilaginous tubercles presenting the ap- 
pearance of warts was placed along its lower edge, and extended 
upwards from that edge ;4,ths of an inch. The largest of these 
were about ,3,ths of an inch in breadth, and less than ;,th of an 
inch in height. They became perceptibly smaller about 8 inches 
from the end of the spinal column, and in the last 3 inches of the 
lower edge were altogether absent. They were composed, as ascer- 
tained by the microscope, of true cartilage. They were implanted 
on avery strong band composed of dense fibrous tissue stretching 
along the whole lower edge of the body. Along the line of junc- 
tion of the cartilaginous and fibrous tissues, there was a thin layer 
of fibro-cartilage. From the upper edge of this fibrous band a 
fibrous lamina ran upwards and became continuous with the 
fibrous lining membrane of the cavity of the abdomen, and behind 
the abdomen it extended upwards along the mesial plane of the 
body to the vertebral column. The lateral line is formed, as was 
ascertained by microscopic examination, by a longitudinal band of 
a peculiar tissue to be afterwards described, which follows the 
