Belonorliynclius and Amblyurus. 355 



to add that the undescribed B. Anningice mnst also be placed 

 here, this being specifically imdistinguishable from B. acutus 

 so far as can yet be determined. The fact is of interest, as 

 considerably curtailing- the known range of the genus Belono- 

 stomus, of which no satisfactory specimens have hitherto been 

 discovered below the lithographic stone of Bavaria and 

 France *. 



Conclusive proof of the generic identity of the so-called 

 Belonostotnus Anningicn with Belonorhynchus is afforded by 

 more than one specimen in the British Museum, but only a 

 single fossil (no. P. 3790) gives much clue to the proportions 

 of its trunk and the characters of some of the scutes. 

 Whereas in the typical B. striolatus the head is about equal 

 to the rest of the body in length, in B. Amiingice it is not 

 more than half as large in proportion ; and the snout of the 

 latter is destitute of the superficial transverse striations charac- 

 teristic of the former. Tlie dorsal scutes, however, upon the 

 middle of the trunk are equally narrow and pointed, and 

 apparently of corresponding form and size. 



This discovery will eventually lead to a more complete 

 elucidation of the characters of Belonorhynchus^ for the Liassic 

 species being considerably larger than the Triassic and its 

 remains occurring in a more satisfactory matrix it will 

 doubtless throw considerable light upon the structure of the 

 skull when exhaustively studied. At present, however, it 

 must suffice to remark that there appears to be a very close 

 resemblance between the skull and mandible and dentition of 

 this genus and the corresponding parts of Belonostomus ; and 

 one fossil lately described f is very suggestive of a large 

 mandibular presymphysial bone, exactly similar to that dis- 

 covered by Otto K,eis J in the Solenhofen Belonostomus. 



The Liassic specimens and a few additional examples of 

 B. striolatus from Kaibl also seem to determine definitely 



* Agassiz (torn. cit. pt. 2, p. 143) named a species from the Stonesfield 

 Slate B. leptodeus, aad Phillips ((ieol. Oxford, 1871, p. 180, diagT, xl. 

 fig. 4) tigured under this nani.j a portion of mandible which might pertain 

 either to Belonustomus or Belonorhynchus. The evidence is very uncertain, 

 and some of the supposed fragments of BelonostoniKS from Stonesfield, so 

 labelled in collections, doubtless belong to a species of Aspidorhynchus, of 

 which Phillips figured a mandibular ramus under the name of '^Pliolido- 

 phorus minor':', Agass." (op. cit. p. 180, dia;^r. xl. figs. 5,0), and of which 

 there are satisfactory specimens in the British Museum. 



t Smith Woodward, " On the Mandible of Belonostomus cinctus, &c.," 

 Quart. Journ. Geo). Soc. vol. xliv. (1888), p. 147, pi. vii. fig. 14. 



I 0. Reis, " Ueber Belonostomus, Aspidorhynehus, uud ihre EeziehuQ- 

 gen zum lebendeu Lepidosteus," SB. math.-phys. CI. bay. Akad. Wias. 

 1887, p. 109, pl. i. fig. 4. 



