1260 DE. ERIK A. STENSIO : NOTES 



evidently run forward dorsally of tl)e basipterygoid process. 

 One of them, the n. ophthaJmicns la,teralis, has pierced the dorsal 

 part of the alisphenoid wulst through an anteriorly running canal, 

 perhaps accompanied by the r. ophthalmicus superficialis tri- 

 gemini, while the other ones certainly had their passage more 

 ventrally on the lateral side of the alisphenoid wulst. From the 

 conditions in Dictyonosteus one can conclude with rather great 

 probability that in Diplocercides the vena jugularis also ought to 

 have passed dorsally of the basipterygoid process. 



Text-figure 5. 



Sbemp.txl- P?-'' alsph Sph p^ 



cr.ep 



IK? /' ,' / • '■ ^\ . ^-TT 'Psph 



Diplocercides kaijseri (V. Koenen). 



Neurocranium from the right side. Cartilage dotted, cartilage hones shaded. 2/1, 

 From Steiisio, 1922 (1922 a). 



JS. 'petlim, exetlimoideo-preethmoid ; Fr, frontal part of the dermal cranial roof ; 

 01, occipito-labyrinth ossification; Pa.it, parieto-interterapoi'al : Fsph, para- 

 sphenoid; S'pli, sphenoid; Siemp.ext, supratemporo-extrascapular ; a.car.int, 

 ventral opening of the unpaired canal for the internal carotid ; alspJi, alisphenoid 

 wulst ; c.n, canal for vessels to or from the nasal fossa (probably a vein canal) ; 

 ?r.ep, epiotic crista; cr.oc, occipital crista; e, basipterj^goid process; feu, 

 anterior division of the myodome ; for., canal probably for a dorsally bounded branch 

 from the n. lineaB lateralis; Zai./or, foramen probably for the anterior branches 

 of the r. maxillaris trigemini and n. buccalis lateralis; olf exit of the olfactorj"- 

 nerve in the nasal fossa ; ophth.lat^, anterior opening of the canal through the 

 alisphenoid wulst for the n. ophthalmicus lateralis ; opJith.lat^, posterior opening 

 of an anterior canal for the n. ophthalmicus lateralis ; II, opticus canal ; III, oculo- 

 motorius canal ; IV, trochlearis canal ; Vje, canal for the r. ophthalmicus jjrofundus 

 trigemini; VII, facialis canal ; VI, probably the canal for the r. palatinus facialis 

 or perhaps the canal for the abducens ; IX ?, presumed position of the glosso- 

 pharyngeus exit; X, canal for the n. vagus, n. lineas lateralis, and v. encephalica 

 posterior. 



In Axelia we have a. foi-m which with regard to the position of 

 the basipterygoid process agrees rather well Avith Diplocercides 

 (Stensio, 1921, text-figs. 39, 40). Moreover, we have tliere a 

 long well-developed homologue to the alisphenoid Avulst of 

 Diplocercides, and on the lateral surface of this homologue, which 



