in Torquigener pleurogramma, for example, the ethmoid 

 is no longer than in, for example, Sphoeroides greeleyi, 

 nor is the entire ethmoid-vomerine region of T. pleuro- 

 gramma shorter than in S. greeleyi, and the frontals are 

 about equally far removed from the anterior end of the 

 ethmoid-vomerine region. Fugu rubripes and Ambly- 

 rhynchotes honckenii likewise have relatively long 

 ethmoid-vomerine regions in contrast to the other species 

 of those genera examined, while these regions are still 

 shorter than in any species of Sphoeroides. The usually 

 greater length of the ethmoid-vomerine region in Sphoe- 

 roides helps to distinguish that genus from the other 

 three, and this moderate length in Sphoeroides can be 

 considered more generalized, for it more closely cor- 

 responds to that of triodontids and triacanthodids than 

 does the usually foreshortened ethmoid-vomerine region 

 oi Amblyrhynchotes, Torquigener, and Fugu. 



While the modal number of vertebrae in Sphoeroides 

 ranges from 17 to 20, only two species have 19 or 20. In 

 Amblyrhynchotes the modal number in the three species 

 studied is 19, and using Fraser-Brunner's (1943) figure of 

 20, the range is 19 to 20. In Torquigener the modal 

 number in the three species studied ranges from 19 to 21. 

 In Fugu the modal number ranges from 20 to 23. Thus, 

 the number of vertebrae tend to be one to several units 

 higher in most species of Amblyrhynchotes, Torqui- 

 gener, and Fugu than in most species of Sphoeroides. 



Figure 267.— Dorsal views of skulls of: left, 

 Torquigener pleuroatictus, 87.1 mm SL, Australia: 

 right, Fugu ehrysope, 98.6 mm SL, Japan. 



Fraser-Brunner (1943) said that Amblyrhynchotes had 

 the frontal evenly narrowed anteriorly, 20 vertebrae, 

 prickles on the side of the body at least behind the pec- 

 toral fin and no ridge along the lower lateral line, while 

 Torquigener (including the species assigned to Fugu) had 

 the frontals much wider behind the prefrontals than 

 between them, 21 vertebrae, no prickles on the side of the 

 body and a ridge along the lower lateral line. As previous- 

 ly discussed, the ridge along the lower lateral line is pre- 

 sent in some species of Amblyrhynchotes as well as in 

 Torquigener and Fugu, although perhaps more common- 

 ly in Torquigener and Fugu. The modal vertebral 

 numbers do not significantly differ, except that Fugu has 

 proportionally more species with more than 20 vertebrae 

 than does Torquigener. At least the species of Ambly- 

 rhynchotes studied here have prickles on the side of the 

 body which are absent in all of the species of Torqui- 

 gener and Fugu studied. 



In the three species of Amblyrhynchotes studied the 

 frontals are of moderate width and gradually taper ante- 

 riorly in honckenii and piosae, very much as in the spe- 

 cies oi Sphoeroides with moderately wide frontals, except 



