366 PROCEEDINGS CF UNITED STATES NATIONAL MUSEUM. 



DIODONTID^. 



Genus OHILOMYCTEEUS Bibron. 



2. Cliilbmycterus geometricus (L.) Kaup. — Swell-toad. 



Very abundant; taken in every seine; sold by small boys as curiosi- 

 ties, at from one to five cents each. 



TETRODONTID^. 



Genus LAGOCEPHALUS Swainson (Gill). 



t 

 {Tet7'odoii Gill, 1. c. The geuus Tetrodon, as first restricted by Swainson, is essen- 

 tially equivalent to Arolhron Miiller, which differs from Lagocephalus in its closed nasal 

 tentacles. The name Lagocephalus is therefore accepted by Professor Gill for the pres- 

 ent genus. ) 



3. Lagocephalus laevigatus (L.) Gill. 



Found by Dr. Yarrow "in small streams running througli salt marshes. 

 But few seen." 



Genus CIEEISOMUS Swainson. 



{Chilichthys Miiller, Gill, 1. c. The genus Cirrhisomua of Swainson (1839) is based on 

 Chiliclitht/8 spengUri {Tetrodon spenglci-i Bloch), and therefore antedates and must super- 

 sede CMVwliihys MUller (1841).) 



The name is given in allusion to the short, fleshy appendages or bar- 

 bels along the sides in the tyi)ical species. These are not found in the 

 other species of the genus, but the name cannot be set aside on that 

 account. Chilichthys may perhaps be retained as a subgeneric name for 

 those species without fleshy slips. 



Cirrisomus difi'ers from Lagocephalus chiefly in the form of the fins. 

 In the latter genus, the dorsal and anal are falcate, of 11 to 14 rays each, 

 and the caudal fin is forked. In Cirrisomus, these fins are all more or 

 less rounded, and the dorsal and anal contain but 6 to 8 rays each. In 

 Lagocephalus, the body is elongate, the caudal peduncle especially so, the 

 skin comparatively smooth, except on the inflated part of the abdomen. 

 There is a fold of skin along each side of the tail below (usually well 

 marked, but nearly obsolete in L. Iwvigatus). The coloration is peculiar, 

 the skin having a metallic lustre. In Cirrisomus, the body is compara- 

 tively short and broad, witli short caudal peduncle. There is usually no 

 fold along the lower side of the tail. The coloration is usually variegated, 

 and without metallic lustre, and the prickles are variously arranged. 

 Four species of Cirrisomus are found on our Atlantic coast: C. turgidus 

 (L.), C. testudineus L., C. trichocephalus (Cope), and C. spengleri (Bloch). 

 The first is common ; the others are rare, or occasional visitants. 



4. CiiTisomus turgidus (L. ) Jor. & Gilb. — Swdl-ioad; Puffer. 



Very common everywhere about Beaufort; taken in the nets with 

 Chilomycterns geometricus. 



