No. 2.] GRAMMICOLEPIS BRACHIUSCULUS. 27 
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fully compared, have resulted in my drawing presented in Fig. 1 
of this memoir. 
Owing to the fact that many parts of the skeleton, from long 
keeping and their delicate structure, have warped considerably 
out of shape, I propose to devote myself on the present occasion 
only to such as seem most important of them, and chief among 
these stands the cranium. 
As I say, so far as I know, the specimen of the cranium of 
Grummicolepis before me is the only one in the hands of 
science, and a most extraordinary object it is. Three features 
strike us most forcibly when we first came to examine it: the 
enormous orbits, the truncate appearance of its anterior part, 
and the semi-transparency of its gelatinous-looking bones. 
Figure 2.— Left lateral aspect of the cranium of Grammicolepis brachiusculus; 
life size, drawn by the author from the specimen. /%, frontal; /a, palatine; S.O., 
supraoccipital; Sg, squamosal; Z/.0., epiotic; P#.0., pterotic; Z.O., exoccipital; 
Op.O., opisthotic; B.O., basioccipital; &s, basisphenoid; Pr.O., prodtic; PZ, post- 
frontal; As, alisphenoid; Os, orbitosphenoid; £72, ethmoid; Prf, prefrontal; Pr.S., 
parasphenoid; Vo, vomer. 
The peculiar rugose condition of a frontal bone, referred to by 
Professor Poey, is well shown in Figs. 2 and 3, #7. It will be seen 
that these rugosities of the frontal radiate from a common cen- 
tre on its superior aspect, this centre being found at about the 
middle of the bone, or what would be the middle of its oblong 
figure were its anterior internal notch completed, and we do not 
regard its postero-lateral prolongation. This latter part of the 
bone forms the superior periphery of the orbit, and is produced 
backwards as far as the squamosal (Sg). To the inner side of 
