28 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I42 



The great variation in the nasal apparatus and dermal bones of the 

 snout in stomiatoids has been demonstrated by Derschied (1924, pp. 

 1 18-128, figs. 12-15). Suffice it to say here that the antorbital-supra- 

 orbital link is present in the more primitive genera Maurolicus, 

 Cyclothone, and Gonostoma. 



The salmonoid nasal sacs seem to be similar to those of the herrings 

 in that a supraorbital and suborbital diverticulum are both present 

 (Derschied, 1924, pp. 109-115, fig. 10). However, the antorbital- 

 supraorbital-maxillary link never seems to be so well developed. For 

 example, in Salmo, which has a very fleshy snout, an antorbital and 

 supraorbital are both present but so deeply embedded that it is diffi- 

 cult to see how opening the mouth could move them. The antorbital 

 and supraorbital are also present in Coregonus (Berg, 1940, p. 235, 

 fig, 122) and Osmerus, though in the latter the antorbital is rather 

 feeble. 



In Argentina there is a well-developed supraorbital covering the 

 supraorbital nasal sac, but apparently no antorbital (Chapman, 1942, 

 p. 106, fig. 4). In Nansenia, however, a small antorbital is present 

 (Chapman, 1948, p. 10, fig. 5). 



In Galaxias there appears to be a supraorbital ( ?) but no antorbital, 

 and in Salanx neither bone is present. Among the haplomous fishes 

 there are apparently no nasal sacs and no antorbital. A movable 

 supraorbital is present in Esox, but not in Umbra. 



In Chanos, which resembles Dorosoma in the heavy layer of adipose 

 tissue in the snout regions, the nasal sacs are again small. The supra- 

 orbital is large but movable and lies on the surface of the skull. The 

 small squarish antorbital covers the outer surface of the nasal capsule. 

 Thus the two bones have planes at right angles to one another, and 

 there seems to be little connection between them. 



Gonorhynchus seems to be unique in that there is a large nasal sac 

 extending back in the flesh external to the large lacrimal. Antorbital 

 and supraorbital bones are absent. 



According to Derschied (1924, p. 159) Phractolaemtis is even more 

 peculiar in having a transverse canal running between the nasal cap- 

 sules of the two sides. 



Among the osteolossoid fishes there is a most varied and disconcert- 

 ing series of dermal bone arrangements on the sides of the snout. All 

 are similar in two respects. First, all the members of the group have a 

 rigid cup around the nasal capsule which gives off no diverticula. 

 Second, the bone arrangements around this capsule in no way re- 

 semble those of any fish dealt with up to here. 



