1736 Bulletin //, United States National Museum. 



spots becoming more marked as the pale streaks fade away ; caudal nearly 

 plain, dusky behind. Length 18 inches. Pacific coast of tropical America ; 

 generally common in sandy bays from Cerros Island to Ecuador; once 

 recorded from San Diego; representing the very closely allied Spheroides 

 testudineus of the Atlantic. Here described from specimens from the Gala- 

 pagos, typical of annulatus. It is possible that the species is not really 

 distinct from Sphwoidea testudineus, but the snout seems a little shorter 

 than in the latter* the head broader and the pale markings more definitely 

 resembling concentric ellipses, (annulatus, ringed.) 



Tetrodon annulatus, JENYNS, Zool. Beagle, 153, 1842, Chatham Island, Galapagos Archi- 

 pelago (Coll. Chas. Darwin) ; STEINDACHNER, Ichth. Beitr., v, 23, 1874. 



Anchisomus geometricus (KAUP) KICHAEDSON, Voyage Herald, 156, pi. 30, 1854, Galapagos 

 Islands ; not of BLOCK & SCHNEIDER. 



Tetrodon heraldi, GUNTHER, Cat. Fish.,vm, 283, 1870, Galapagos Islands and Panama; 

 after RICHARDSON'S specimen, prickly and with the interorbital space broad and flat. 



Tetrodon geometricus, GUNTHER, Fish. Centr. Amer., 489, 1869. 



Sphceroides testudineus annulatus, JORDAN & EDWARDS, I. c., 240. 



Represented northward (Guaymas, Mazatlan, La Paz, etc.) by 



2151a. SPHEROIDES ANMJLATUS POLITUS (Girard). 



This form differs usually in having the small dark spots smaller, more 

 numerous, and more unequal in size than is usually the case in Spheroides 

 annulatus of the same size. It is also more frequently devoid of prickles, 

 but this character seems to be subject to great variation. At Mazatlan 

 smooth and prickly specimens abound in the Astillero, and may be taken 

 together in the same drawing of the net. Professors Evermann and Jen- 

 kins further note that the interorbital space is flat in S. politus and con- 

 cave in S. annulatus, but we are unable to appreciate any such difference 

 in the comparison of politus from Mazatlan with annulatus from the Gala- 

 pagos. The difference in the size of the spots is, however, tangible and 

 apparently fairly constant, (politus, polished.) 



Tetrodon politus, GIRARD, Pacific K. K. Survey, x, 340, 1858, San Diego, California, speci- 

 mens perfectly smooth; GUNTHER, Fish. Centr. Amer., 489, 1869 ; GUNTHER, Cat., vm, 

 281, 1870 ; JORDAN & GILBERT, Synopsis, 860, 1883. 



Sphceroides politus, JORDAN & EDWARDS, 1. c., 239 ; EVERMANN & JENKINS, Proc. TJ. S. Nat. 

 Mue. 1891, 165. 



2152. SPHEROIDES FORMOSTJS (Giinther). 



Head 3; depth 2 to 3; snout 2f in head; eye 5 to 5. D. 7; A. 7. 

 Body short and stout, the head short and very broad, the snout short, 

 slightly convex, and not very steep ; interorbital space very broad, flat, 

 with a median bluntish ridge, its width 1 in snout, 2f in head ; no cirri ; 

 nostrils in a very short, thick tube, with very large, slit-like openings 

 extending to base of tube; outer opening wholly lateral, but the inner 

 encroaches largely on the anterior face of the tube ; back, from nostrils to 

 dorsal, with rather small, sharp prickles, close set anteriorly, sparse poste- 

 riorly ; belly, from throat to vent, everywhere with small prickles ; head, 

 sides, and caudal peduncle with smooth skin; fins rather small; caudal 



