11 
General Form . — The type-specimen (PL III, Pig. 2) measures 0‘2G5 
in length, and is j^erhaps as large as any indicated in the collection. Com- 
pared with 31. Clarkei, the fish is much less elongated, the greatest depth of 
the trunk being only comprised a little more than three and a half times in 
the total length, the tins are less powerful, and the scales are exactly twice 
as large in proportion. 
Head and Opercular Apparatus. — No details of cranial osteology can 
he deciphered, and little beyond the general form of the head is determinable. 
In accordance with the other proportions of the fish, it is relatively shorter 
than in M. Clarkei, and the mandible perhaps stouter. An element of the 
upper jaw, either the maxilla or the palato-pterygoid, is long and narrow, 
though deepest behind, and remains of the actual maxilla in No. c show 
that it was externally ornamented by large rngm and tubercles. The dentary 
bone, bearing at least a few spaced conical teeth, is superficially ornamented 
by striations parallel to its long axis. 
Appendicular Skeleton. — At the postero-inferior angle of the lower 
jaw in No. c, a large, elongated, triangular bone is observed, evidently to 
be regarded as the left infraclavicular element of the pectoral arch. This 
bone is shown of twice the natural size in PI. Ill, Pig. 3, the short base-line 
being posteriorly and the apex anteriorly directed, and its external surface is 
ornamented by coarse, rounded, radiating rugm, proceeding upwards and 
downwards from an unsymetrically-placed longitudinal ridge. The form 
and proportions of the other bones of the pectoral arch cannot be determined, 
and in the figure of the type-specimen (PI. Ill, Pig. 2) the positions of the 
paired fins can only be 2 )artially marked by dotted lines, based upon the 
evidence of a second fossil. No. h. None of the fins are capable of descrip- 
tion, but, so far as determinable, they agree well with those of 31. Clarkei. 
Squamation. — The size of the scales renders it easily possible to observe 
their variations in form. Upon the flanks they are deejier than broad, and 
in a specimen O' 265 in length, the antero-posterior measurement of each is 
about 0’002. Vcntrally, all the scales become much broader than deep, and 
upon the upper lobe of the tail they are diamond-shaped and elongated. 
There is also a singular feature, well displayed in the type-sj)ecimen (PI. Ill, 
Pig. 2), immediately above the anal fin, about nine series of scales being 
reflexed forwards, as in the Platysomidae. 
lla 74—90 E 
