1264 DK. ERIK A. STEXSIO : NOTES 



this difference is due to the upward displacement of tlie 

 articulation between tlie primordial neurocranium and the 

 palato-quadrate in the Ooelacanthids (Stensio, 1922 a, pp. 205- 

 206) from its original position at or near the base of the 

 neui'ocranium." 



" For if we turn to Dictyonosteus we find there a large basi- 

 pterygoid process which certainly extends some distance upivards 

 along the lateral surface of the neurocranium but which issues, 

 however, also in part from the cranial base. This basipterygoid 

 process really forms, if one will so express it, a very powerfid 

 ' wulst ' along the posterior edge of the sphenoid {cf. Stensio, 

 1921, p. 56) where it begins immediately above the para- 

 sphenoid — i. e. at the basis cranii — and continues upwards and 

 somewhat backwards to about a third of the height of the 

 nt'urocranium at this place, ending there with a truncated upper 

 end. On account of the oblique position of the process the 

 anterior surface of this is directed antero-dorsally and the 

 posterior one postero-ventrally. The process has in addition a 

 dorsal surface and has certain!}" also had another one against 

 which the meta.pterygoid probably articulated. This latter 

 surface, which probably faced ventro-laterally and perhaps some- 

 what posteriorly, is, however, not well preserved." 



" Tiie antero-dorsal surface of the basipterygoid process and 

 the lateral VN-all of the part of the sphenoid just in front of the 

 basipterygoid process in Diciyonosteus form together a sort of 

 shallow antero-laterally and somewhat dorsally directed fossa at 

 the inner end of- which the Vi^ell-developed cana,lis traaisversus 

 opens. The vena jugularis has passed the opening of this canal 

 and received the vena pituitaria from it, after which it has 

 continued upwards and backwards in a very distinct sulcus on the 

 boundary between the external vertical surface of the sphenoid 

 and the antero-dorsal surface of the basipterygoid process, until 

 it reached the dorsal surface of the latter process, where it 

 presumably turned more straight backwards, situated all the 

 time close to the lateral surface of the sphenoid. The arteria 

 carotis interna must in its forward course have been situated 

 on the outside of the basipterygoid process close to its base. At 

 the anterior end of the basipterygoid process it must have turned 

 in a medial direction, entering a sphenoid by a large foramen. 

 The parasphenoid lacks the processus ascendens, but if this had 

 been developed the arteria carotis interna, would have passed 

 between it and the basipterygoid process to its canal in the 

 sphenoid just referred to." 



"From the upper end of the basypterj^goid process a ridge, 

 which if not strong is still distinctly marked, passed upward and 

 forward to the cranial roof ; and just in front of this ridge, which 

 I have called the alisphenoid ' wulst," Ave find at the top not far 

 below the cranial roof the anterior opening of a canal, which, as 

 far as one can judge (cf. Stensio, 1921, pp. 60, 93), must have 



