484 BULLETIN 189, UNITED STATES NATIONAL MUSEUM 



description of C. rotundatus Meek and Hildebrand (see reference 

 above), was based. These authors regarded the Panama material 

 as identical with specimens from Japan, which may be correct. How- 

 ever, there are insufficient specimens available for study to prove it. 

 Accordingly it seems advisable to retain provisionally adspersus of 

 Tschudi for the American representatives. As the specimen de- 

 scribed by Tschudi was about 250 mm. long, whereas the largest one 

 now at hand is only 72 mm. in length, there naturally are some dis- 

 agreements, though apparently none that cannot be ascribed to age. 

 The same remarks apply to a specimen 360 mm. long, from Cocos 

 Island, described by Snodgrass and Heller (1905, p. 407) as C. 

 angulosus. 



Range. — Panama Bay, Cocos Island, and Peru. 



Family TETRAODONTIDAE: Puffers 



Body oblong, robust; belly capable of great inflation either with 

 air or water; head large; mouth small, terminal; teeth fused into a 

 plate, in each jaw, each plate with a median suture; gill opening 

 reduced to a slit situated immediately in front of pectoral; true scales 

 usually absent, the skin often being covered with spinules or prickles, 

 most commonly present on back and belly; dorsal fin single, inserted 

 posteriorly, consisting of soft rays only; anal similar to dorsal, and 

 generally more or less opposite it; ventral fins wanting; pectorals short 

 and broad. 



The puffers are sluggish shore forms of the warmer seas. A single 

 genus is known to occur in Peru. 



Genus SPHOEROIDES Lacepede, 1798 



Body oblong, plump, capable of considerable inflation; nostril with 

 a short transverse tube with a small opening at each end, inside of 

 tube smooth or with folds of skin; skin largely smooth to partly or 

 almost wholly covered with prickles, sometimes with scalelike dermal 

 development, and occasionally with dermal flaps; dorsal and anal 

 similar, small, each with about six to eight rays; caudal usually with 

 a straight or convex margin, rarely concave. 



Two species are included in the Peruvian collections studied, one 

 of which apparently is new to science. 



KEY TO THE SPECIES 



a. Spinules wanting on snout and posterior to origin of dorsal and of anal, and 



along middle of side; pectoral with 16 rays annulatus (p. 485) 



aa. Spinules present almost everywhere, extending forward on snout and on tail 

 behind dorsal and anal fins; pectoral with 14 or 15 rays, 



sechurae, new species (p. 486) 



