I 



12'4 Mr. C. T. Regan 07i the Anatomy and 



Other features of the head skeleton are shown by the 

 figures, and it need only be remarked tliat the form of the 

 cranium, the development of the temporal fossse, the general 

 character and arrangement of the frontals, parietals, the otic 

 bones, the nasals, circumorbitals, and supraniaxillaries indi- 

 cate a pretty close relationship to generalized isospondylous 

 fishes such as Elops [cf. Ridevvood, P. Z. S. 1904, ii. pp. 35- 

 81, c. figg.). 



The vertebral column only differs from that of the Elopidae 

 in that the centra are coossified with the arches ; there are 

 52 vertebrae ; the centra are perforated ; the ribs and epi- 

 pleurals are inserted together on very short processes which 

 increase in length posteriorly and there is a series of epi- 

 neurals ; the caudal fin skeleton differs from that of the 

 Elopidge chiefly in that there is only one upturned centrum 

 which is rather elongate. 



The general characters of the pectoral arch and the pelvic 

 bones are shown in the figures, and it is only necessary to 

 say that the forked post-temporal is firmly attached to the 

 epiotic above and the opisthotic below, and to call attention 

 to the remarkable posterior processes of the pelvic bones. 



This family includes the single recent genus Aulopus, with 

 the allied Cretaceous Sardim'oides. 



Macristium^ Regan, is probably related to Aulopus. 



The genus Scopelosaums (Bleeker, Act. Soc. Sci. Ned. Ind. j 



viii. 1860, no. 5_, p. 12) appears to differ but little from 

 Aulopus in the head, mouth, dentition, &c. The body is 

 very elongate, subcylindrical, and has 3 rows of luminous 

 spots on the belly ; there are 9 branchiostegals. 



The vomerine teeth form a single transverse series, and 

 this character indicates a closer relationship to Aulopus than 

 to the Myctophidge. 



Family 2. Synodontidse. | 



Differ from the Aulopid^e in certain features of specializa- 

 tion. The suspensorium is directed obliquely backwards and 

 the mesopterygoid is less developed than in Axdopus ; the m 



mouth is wide ; there is no suprainaxillary, and the slender ■ 



maxillary is firmly adherent to the prEemaxillary or is united ■ 



with it by suture or ankylosis ; there are bands of curved 

 pointed teeth in the jaws and on the palate ; the branchio- 

 stegals number 11 to 17. The cranium in Syyiodus and 

 Saurida is more depressed than in Aidopus, with the epiotics 

 further apart and the posterior temporal fossge much reduced 

 in size ; the parasphenoid is laminar and the orbitosphenoid 

 forms a thin septum ; the upper fork of the post-temporal 



