of the Fishery Board for Scotlmid. 
323 
prominence with a smaller tooth. From what appears to correspond to 
the lower margin of the pre-opercular region, two prominent spines project 
outward and backward. The branchiiw have simple papill.-B. The body 
tapers gently from the head to the tail, the notochord passing nearly 
straight out in the latter, though a considerable hypural thickening 
exists inferiorly. The dorsal marginal fin begins behind the head and 
joins the caudal. Ventrally it extends from the anus to the caudal. The 
latter shows only embryonic rays, and these are less distiaictly marked 
throughout the marginal fin — dorsally and ventrally. The pectorals form 
two rather large and long organs, apparently with true rays, the upper 
and lower being short, the median much longer. They are deeply tinted 
with black pigment on the inner surface, or what probably is the 
ventral surface in action. It is chiefly developed in the interradial 
integument. Two pigment-specks occur near the middle line in front of 
the eyes, four symmetrically placed over the mid-brain, with, several 
chromatophores in the middle line behind, the only others being a few at 
the base of the pectorals ventrally, and along the ventral margin in the 
posterior third of the body. 
It is difficult, as well as uncertain, to assign the relationship of this 
form. All that can be said at present is, that the form of the mandible 
and the dentition point to a fish peculiar in this respect. 
7. On the Young Stages of Cottus. 
Three interesting stages were procured in the ' Garland,' west of the 
Island of May, at the surface, on the 29th April 1890. The smallest of 
these measures 7 mm. It is a comparatively short fish, with a prominent 
abdomen and projecting anus. In spirit, large black chromatophores 
occur on the snout and head, and are continued backward on each side of 
the dorsal fin fully to a vertical line from the vent. From behind the 
pectorals a transversely-arranged series of the same pigment-corpuscles 
extends in a diminishing ratio to the anus. They thus, as in certain 
other forms, characterise the upper region of the abdomen. The terminal 
portion of the notochord is nearly straight, and the somewhat rounded 
tail-fin has embryonic rays. A thickening, however, is noticeable inferiorly 
in the region of the hypurals, and traces of permanent rays also exist. 
The dorsal presents embryonic rays, with true rays developing close to 
the line of the body. No differentiation of the first dorsal has yet taken 
place. A similar condition exists in the anal, though the permanent rays 
are less developed. The head of the specimen is injured, but a sharp 
spine is visible on each side at the occiput. None appears above the eyes. 
The other two specimens are about equal in size, and represent nearly 
the same stage, viz., at 9*5 mm. (PI. X. fig. 6). The snout is now somewhat 
more prominent, though blunt at the tip, and dorsally marked by sym- 
metrical touches of black pigment, which occur at the tip, at the nasal pits, 
and in connection with the brain. The peritoneal pigment is conspicuous 
at the upper region of the abdomen, and there are touches of the same black 
pigment laterally on the opercular region and inferiorly on the hyoidean. 
The body is deeper and longer, and the black pigment passing from the 
occiput along each side of the dorsal fin has posteriorly extended as a 
broad bar to the ventral margin. The posterior border of this bar is 
comparatively straight, and marks the end of the middle third of the fish. 
The development of the hypural elements has pushed the terminal regiou 
of the notochord upward, and true fin-rays are formed along the ventral 
portion of the caudal. Both dorsal and anal fins have, for the most part, 
embryonic rays as before. The occipital spine is longer, and another, 
