GILBERT AND STAKKS — FISHES OF PANAMA BAY 

 Measurements in Hundredths of Length without Caudal. 



157 



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 



Termination of dorsal from caudal 



Termination of anal from caudal 



Number of dorsal rays 



Number of anal rays 



151 



34 

 7J 



n 



i7i 



i7i 



15 



25 



14 



i3i 



289. Spheroides annulatus (Jenyns). 



Appearing frequently in the Panama market. The young are common also 

 in the tide-pools, associated with the young of Tetraodon hispidus. In the young, the 

 concentric rings are less variable and less interrupted than in adults. The ground 

 color of the back is generally not broken up into small spots, as is so frequently the 

 case in adults. The spots on the sides are usually larger and fewer in the young, or 

 are sometimes entirely absent. The caudal is rather abruptly blackish upon its pos- 

 terior half, the other fins are colorless. 



One specimen, 15 cm. in total length, differs from all the others in the some- 

 what more prominent sharper spines, and the very different coloration. Upon the 

 middle of the back is an S-shaped marking, the extremities of which are equidistant 

 respectively from the eye and the front of the dorsal, the interval being in each case 

 twice the diameter of the eye. Around it are very irregular incomplete rings. A 

 curved line runs from just behind the eye to the middle of the gill-opening and another 

 from the nape to above the base of the pectoral fin. Across the snout and caudal 

 peduncle are irregular lines. The sides have fewer spots than is usual, and the fins 

 are as here described for the young. The measurements of this specimen are the 

 third listed in the appended table. 



We have examined specimens from Mazatlan, La Paz, and the Galapagos 

 Islands. Some of the larger northern specimens {8. politus) have the color of 



(21) December 23, 1903. 



