798 



REPOET OF COMMISSIONER OF FISH AND FISHERIES. 



[52] 



Independent epiotic, opistliotic, sphenotic (postfrontal), and prootiu 

 osseous elements are represented in the auditory capsule, but the pro- 

 otic is the only one that passes through the cranial wall to be discerned 

 upon the inner aspect of the brain-case. The pterotics are absent. 



By the i^roper interchange of the nomenclature, minute descriptions 

 of all these elements are contained in Part I. Bridge's descriptions 

 are also terse and clear. For those who may by chance in their reading 

 wish to compare the investigations and studies of Bridge upon the 

 cranium of Amia, in his article in the Journal of Anatomy, with Part I 

 of this paper, the following table will be found to be useful in the con- 

 nection, presenting as it does in a concise form a few of the differences 

 interminology employed by these two authors ; where the number of the 

 figure is giv^en in parentheses it is reproduced in this memoir. 



Table. 



Shufeldt. 



Pigures and let- 

 tering. 



Bridge. 



Ethmoid 



Nasal 



Septomaxillary . 

 Preni.ixillary. .. 



Preoibital.- 



Prcfiontal 



Fi^ontal 



Postfrontal 



Parietal 



Squamosal 



Supratemporal j Figs. 1, 16 -^ (S, 



I _ t x>- and Esc ) 

 Posttemporal 



Fig. 14-(JS;«A.) 

 Pig.l4-(i!^a.) 

 Pig.3+(«'ma;.) 

 P'g. 2 + (Pmx.) 

 Pig. 1 {An.) 

 Pig. 3 + (Pr/.) 

 Pig. 16+ (F.or 



Fr.) 

 Fig. 3+ {Psf.) 

 Fig. 1 + (Pa.) 

 Fig. 1 +(«(?.) 



Ethmoid 



Nasal - 



Septomaxillary . 



Preniaxilla 



Preorbital , 



Prefrontal 



Frontal , 



Exoccipital 



Baslocoipital 



Epiotic (^p. o) 



Prootic (Pr.o).... 

 Pterotic (absent) . 

 Opisthntic (Op. o). 



Vomer 



Paiiisphenoid 



Orbitospbcnoid. .. 

 Ahspbenoid 



Fig. 1, 16 + (Sc. 



ovPst. T.) 

 Fig.l + (Oi) 

 Fig. 5 + (Ob.) 

 Fig. 5-t-(JSa;.) 

 Fig. 5 + (Pe.) 



Postfrontal (sphenotic)... 



Dermo-supraoccipital 



Parietal 



Supratemporal 



Posttemijoral . 

 Exoccipital . . 



Fie 3 + (Jc.) 

 Fig. 2+ (Yo.) 

 Fig. 2+ (Ps.) 

 Fig. 2 + (Os.) 

 Fig. 2 + (As.) 



Epiotic (Ep. o) . . 



Prootic 



Absent 



Opisthotic 



Vomer 



Parasphonoid . - . 

 Orbitosphenoid 

 Alisphenoid 



Ethmoideum. (Eth.) 

 Nasale. (Na.) 

 Septomaxillare. (Smx.) 

 Praemaxillare. (Pmx.) 

 Antorbitale. (An.) 

 Prsefrontale. (Prf.) 

 Frontale. (F.) 



Postfrontale. (Psf.) 

 Parietale. (Pa.) 

 Squamosum. (Sq.) 

 Extrascapula. (Exc.) 



Suprascapula. (Sc.) 



Occipitale laterale. (01.) 

 Occipitale basilare. (Ob.) 

 Occipitale externum . (Ex.) 

 Petrosum. (Pe.) 

 Absent. 



Intercalare. (Jc.) 

 Vomer. (Yo.) 

 Parasphenoid. (Ps.) 

 Orbitosphenoid. (Os.) 

 Alisphenoid. (As.) 



A + means other figuies than the one quoted in ihe second column show the same bone similarly 

 lettered. 



The mucus canals have been so thoroughly treated in Part I that I 

 will not revert to them agam here. In the mandible the single ramal 

 bnineli commences in the angular element to pass through the dentary 

 for its cutire length, to meet the fellow of the opposite side at the sym- 

 phytiis. This branch connects with the system of the rest of the skull, 

 ^^iiere the angular articulates with the preoperculum, through which 

 latter bone the lateral mucus canal passes, after haviug traversed the 

 supratemporal and squamosal. 



Both the orbitosphenoids and alisplienoids are more or less circular 

 bones. This is due to the fact that during their extension and develop- 

 ment they have not proceeded sufficiently far as to impinge upon neigh- 

 boring osseous elements for the major part of their i>eripheries. The 

 Xjosition of these bones is well shown in Fig. 3, and others. 



