NO. 1287. JAPANESE TRIG GER-FISHE^ JORDAN AND FOWLER. 279 



guide in the arrangement of the species of the genus," and we find it 

 diflicult to define more than two genera in the family, unless we assign 

 generic rank to each of the leading sections. In Japan three of these 

 sections are represented, Tetrosomus, Lactmna^ and Ostracion. The 

 remaining four, Rhinemmus, Chapinm, Laeto2jhryi<, and Aeauthostra- 

 clon, are all based on the 3-angled species, a type contined to the AVest 

 Indian Region, and by Jordan and Evermann taken as a distinct 

 genus, Lacto2>hrys. This division into 3-angled American species, 

 Lactoi}Ju'i/!<. and 4-angled Asiatic species O drachm, is here accepted. 



a. Tetrosomus. Carapace 5-angled, the dorsal ridge surmounted by a very high spine; 



plates of sides with dark spots gibbosum, 20 



(((/. Carapace 4-angled; the back witliout conspicuous central ridge and with a small 

 spine or none, carapace closed behind the dorsal fin. 

 h. Ostraciov. Carapace without spines anywhere; plates of sides with blue spots. 



iminaculatiuu , 21 

 bb. Lactorla. Carapace with spines, one before each eye being conspicuous. 

 c. Frontal spines, short, divergent; center of back with a spine, a small spine 

 opposite it on each lateral ridge; ventral ridge with a spine behind and 

 usually two smaller ones before it; caudal fin moderate; plates somewhat trans- 

 lucent diaphanum, 22 



<-r. Frontal spines very long, directed forwards; ventral ridge with a long spine 

 l)ehind; a low, blunt spine on back; caudal fin very long in the adult, with 

 black spots - comutwn, 23 



20. OSTRACION GIBBOSUM Linnaeus. 



Ostracion gibbosus Li^tsmvh, Syst. Nat., 10th ed., 1758, p. 331; India (after Ostra- 

 ckm qiutdrangulus gibbosns of Artedi).— GCnther, Cat. Fish., VIII, 1870, 

 p. 258; Zanzibar, Persian Gulf, Borneo, India. 



Ostradun turritus FoeskAl, Descr. Anim., 1775, p. 75; Red Sea.— Bleeker, Verb. 

 Ak. Wet. I, 1853, p. 15; Kaminoseki, Inland Sea of Japan.— Bleeker, Atlas 

 Ichth., V, 1865-69, p. 31, pi. iii, fig. 3; Java, Celebes, Buro, Amboina, 

 Ceram.— Goode, Proc. U. S. Nat. Mus., 1879, p. 21, and of most authors. 



Loctophrys camelinus Dekav, New York, Fauna, Fishes, 1842, p. 341, pi. lviii, 

 fig. 190 (recorded by error from Long Island). 



Head 3; depth If; D. 9; A. 9; P. 10; scales 9 from gill opening 

 to end of carapace, 11 across widest part of carapace below, and 8 

 between spine on the back and outermost lateral spine. Eye 2 in 

 head and 1^' in snout; snout obtuse, inferior, very little depressed 

 above; interorbital space concave; mouth small, lips rather thick; 

 teeth small and pointed; nostrils small and directly in front of eye; 

 supraorbital ridge with a well-developed spine. Carapace Avith 4 

 ridges, the upper 2 much closer together than the lower ones, along 

 which are 2 low postocular and 1 low posterior spines on each side; 

 median ridge of the back forming a large, compressed, elevated, and 

 triangular spine curving backward; ventral ridges furnished with 5 

 spines on each side curving l)ackward, the iirst one of which is small; 

 gill slit short, directly ))ehind the eye; dorsal small, entirely in 



