158 



CALIFORNIA ACADEMY OF SCIENCES 



the back broken up into smaller spots than in the .southern specimens, thoujj;h some 

 of the smaller northern specimens are like the southern in this as in other respects. 

 Spheroiiks polUus has been recorded from Panama (Jordan & Bollman, 188i), p. 183) 

 and from Santa Helena Bay (Boulen^or, 1808- 1)9, Vol. 14, p. 8). We consider it 

 identical with inunt/atiis. The Galapagos specimens vary greatly in depth of color. 

 One has the back, pectoral, dorsal, and caudal very dark brown, almost black, while 

 the anal is dark. The color of the back grades in other sjiecimens to light brown, 

 while the tins are nearly colorless. One specimen differs from the others in having a 

 very concave interorbital. 



Mtasiircmoils in Himdrcdths of Length without Caudal. 



Locality 



Panama 



Galapagos 



La 



Paz, 

 Mex 



Mazatlan, 

 Mex. 



Length without caudal in mm 



Head from teeth to middle of gill-opening. 



E)epth at occiput 



Orbit 



Interorbital (bone) 



Snout (from teeth) 



Length of dorsal 



Length of anal 



Length of caudal 



Distance from tip of dorsal rays to caudal . 

 Distance from tip of anal rays to caudal.... 



Number of dorsal rays 



Number of anal rays 



200 



37 

 24 



5i 

 13 

 20J 

 18 

 \b\ 

 24 



9i 



9i 



8 



7 



158 



36i 



24 



7 

 12 



19 

 18 

 i6f 

 26 



8 

 8 

 7 



121 

 36J 

 24i 



5i 



9 



16J 

 18 



15 

 26 

 10 



9i 

 8 



7 



170 



34 



25 



7 

 loj 



20 

 '18 



25 



8 



n 



185 



35 

 24 



6 

 12 

 18^ 



19 

 16 J 



24 

 7 

 8 

 8 

 7 



200 



34 

 24 

 4i 



18 

 19 

 17 

 24 

 8 



n 



116 

 35 

 24 



8 



10 

 18 



19 

 i6i 



25 

 9 

 9 



215 

 36 

 24 

 5i 

 13 

 20 



19 

 16J 



24 



8 



7 

 8 



114 

 36i 



23 



6 

 10 

 18 

 18 

 i5i 

 25 



9 

 10 



8 



7 



92 



35 

 22 



7 



7i 

 18 



17 

 16 



25 

 10 

 10 



8 



7 



290. Spheroides furthii (Steindachner). 



A rare species, not taken by us; recorded from Panama by the describer, 

 and by Jordan (1885, p. 393) from the Gilbert collection. 



Guentheridia gen. nov. (Teiraodoniidce). 



Type, Tetrodon formosus Giinther, 1870, p. 283. 



This genus differs from Spheroides in the character of the olfactory organ, 

 which is a transversely-placed tube, open at each end to its full diameter. The outer 

 end is squarely, the inner obliquely, truncate, making the upper margin of the tube 



