184 On the Osteology dsc. of the Order Scleroparei. 



and outwards from the neural arches ; corresponding ventral 

 processes are developed from the fourteenth to the nineteenth. 

 In D. volitans none of the prtecaudal vertebras have transverse 

 processes; the united anterior vertebrse bear a prominent 

 neural crest and the first is sutured to the basioccipltal and 

 supraoccipital ; in D. orientalis the united anterior vertebra 



Fig. 5. 



-pror pror- 



, , lelh 

 -lei-?? 



--pop- 



Skulls aud anterior vertebrre of A. Dactyloptena orientalis and 

 B. Dactylopterus voUtcms, seen from above. 



pror^ praeorbital ; m, nasal ; leth, lateral etlimoid ; /, frontal ; p, parietal ; 

 c, commissural bones ; spo, sphenotic ; pto, pterotic ; epo, epiotic ; 

 soc, supraoccipital ; eoc, exoccipital ; 2^tte, post-temporal ; v, Vi, v^, V3, 

 vertebrae. 



have only a low neural crest, but they have transverse pro- 

 cesses which form a continuous shelf on each side ; those of 

 the first vertebra are sutured to the exoccipitals and post- 

 temporals, whilst those of the third are produced outwards 

 and curve forwards to join the extremities of the post- 

 temporal ; tiie anterior free prgecaudals have transverse 

 processes which decrease backwards and are absent on the 

 last two. The two genera also differ in cranial structure, 

 for in D. volitans the epiotics meet behind the supraoccipital 

 and in front of them the commissural bones appear as con- 

 stituents of the cranial roof, whereas in D. orientalis the 

 epiotics are separate and their inner edges diverge backwards. 

 Also in D. volitans the praeorbitals meet at the end of the 

 snout, but in D. orientalis they are well separated. 



