158 



CALIFORNIA ACADEMY OF SCIENCES 



the back broken up into smaller spots than in the southern specimens, though some 

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

 Sjjheroides politus has been recorded from Panama (Jordan & Bollman, 1889, p. 183) 

 and from Santa Helena Bay (Boulenger, 1898-99, Vol. 14, p. 8). "We consider it 

 identical with annulatus. 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 specimens to light brown, 

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

 very concave interorbital. 



Measurements in Hundredths of Length without Caicdal. 



Locality 



Length without caudal in mm 



Head from teeth to middle of gill-opening. 



Depth 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' 



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. {Tetraodontidce). 



Type, Tetrodon formosus Giiuther, 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 



