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59 



observe behind the orbil, in addition to the supraoccipital (so) and the frontals (/r), 

 a small posttrontal (pf), a large pterotic (scpiamosal, sq) and a small postteniporal 

 (supraclavicular I, pt). The last is attached by a wedge-shaped suture to the 

 pterotic, the only bone with which it enters into contact on the side, whereas on 

 the posterior aspect of the skull it extends upwards to the epiotic (fig. 11). The 

 epiotic (ep) is not visible from the side; it is covered here by the frontal, which 

 by means of a prolongation reaches right back to the posterior surface of the 



Fig. 10. 



Amphisile scntata. Skull from the left sidf. .so 

 sf/: pterotic fsquaniosal): fr: IVontiii: /)/': 

 nasal: ao: anlorhital : a. a": flctachi'd parts 

 operculum: s: suboperculum. Tlic <l( 



■ipital; pt : jiostteniporal (sui>raclavicnl 

 il ; prf: jirefontal. tlics: niesetliinoid 

 lie: qii : (juadrate; prit: preopereului: 

 udieales llie canal lor tlie lateral line. 



skull, projecting in between the pterotic and the supraoccipital; a slightly shorter 

 prolongation is sent by the frontals into the supraoccipital. The triangular piece 

 of the supraoccipital thus included between these prolongations of the frontals 

 might very easily be taken for a separate bone (thus by Starks (30) who describes 

 it as belonging to the epioticum). Parielals are wanting; also opisthotics. On the 

 part of the skull lying in front of the orbits we have, in addition to the frontals, 

 a small part of the prefrontals iprf) between the nasal openings and the orbits; the 

 remainder of the prefontal is covered by the large ant- or preorbital (ao) which 

 is triangular in shape and anteriorly sharply pointed. This has a sharp border 

 below for a very long distance, a small curved incision above for the nasal openings 

 and is connected otherwise by a long suture to the nasal (na), which is sutured 

 at its long anterior end to the vomer, but does not reach quite to the extreme end 

 of the latter bone. The anterior half of the nasal is pierced by a canal for the 

 lateral line in continuation of the canal which passes through the frontals; of the 

 remaining bones the postfrontal and the pterotic also contain a lateral line canal. 

 On the posterior aspect of the skull (fig. 11), the two epiotics (ep) meet together 

 for quite a short distance round the foramen magnum and thus exclude the 

 supraoccipital (so) from the latter; we see further the exoccipitals (eo), attached 

 laterally by a suture to the posttemporals (pt), of which much more is seen than 

 from the lateral aspect; on the lower, inner border of each exoccipital, close to 



