7. OSTRACION. 205 



middle of the back ; no spine on the kiteral dorsal ridge. Ventral 

 ridge terminating behind in a strong claw-like spine, bnt withont 

 other spines. Interorbital space deeply concave. Caudal fin 

 of moderate length. Body with irregular bluish and blackish 

 markings. 



Indian Ocean and archipelago. 



a. Adult (5 inches long) : skin. Zanzibar. From Lieut.-Col. 



Playfair's Collection. 



b. Half-grown. Zanzibar. From Lieut.-Col. Playfair's Collection. 



c. Adult. Mozambique. Presented by Dr. Livingstone. 



d. Adult. Amboyna. From Dr. Bleeker's Collection. — Type of 0. 



pentacctnthus. 



e. Half-grown: skin. 



17. Ostracion cornutus. 



Waiucjhbif, Append, p. 20. no. 12, tab. J. 13. fig. 1 ; Valent. pp. 358, 



451, 455, 4(31, figs. 36, 333, 344, 3G7; Binjsch, pp. 9, 10, 17, tab. 5. 



figs. 8 & 20; tab. 9. fig. 8; Eenard, i. tab. 39. fig. 197, ii. tab. 8. 



fig. 38, tab. 13. fig. 60, tab. 27. fig. 135 ; Seba, iii. tab. 24. figs. 8, 



9, & 13. , . . '.. 



Crayracion no. 26, Klein, Pise. Miss. iii. p. 22. 



Ostracion, sp., Gronov. Mus. i. p. 54. no. Il8 ; Zooj)hyl. p. 45. no. 175. 

 Ostracion cornutus, L. Si/st. Nat. i. p. 409; Block, i. p. l05, tab. 133; 



JBl. Schn. p. 500 ; Zacq). i. p. 470 ; Shmo, Zool. v. p. 223, tab. 170 ; 



Schleg. Faun. Japmt. Poiss. p. 299, tab. 131. fig. 4; Bleek. Verh. 



Pat. Gen. xxv. Palist. p. 32 ; Hollard, Ann. Sc. Nat. 1857, vii. 



p. 158 ; Peters, Monatsb. Ak. Wiss. Bert. 1868, p. 460. 



areas, Bl. Schn. p. 502. 



Ostracium cornutum. Cant. Mai. Fish. p. 365. 



Ostracion valentini, Bleek. Joiirn. Ind. Archipel. 1848. 



(Acanthostracion) arcus, Bleek. Atl. Ichth. Ostr. p. 35, pi. 2. 



tig. 3, pi. 4. fig. 4. 



Carapace four-ridged, forming a broad bridge across the back of 

 the tail. A long conical spine above each orbit, pointing forwards. 

 Each ventral ridge terminates behind in a similar long spine point- 

 ing backwards. Each dorsal ridge with a slight prominence in the 

 middle of its length, but it is not developed into a spine. Median 

 line of the back slightly raised, without spine. Interorbital space 

 deeply concave. Caudal fin rery long in adult examples, with 

 simply bifid rays. Carapace and tail with round bluish and blackish 

 spots in moderate number, of the size of the pupil of the eye. 



Indian Ocean and archipelago ; Micronesia. 



a-h. Half-grown; Port Natal. Purchased of Mr. Ayres. 



c-d. Adult and half-grown : skins. Zanzibar. From Lieut.-Col. 

 Playfair's Collection. 



e,f. Young. Zanzibar. 



g. Young. Seychelles. From Prof. E, P. "Wright's Collection. 



h. Young : skin. Indian Ocean. Presented by Sir A. Smith. 



i, k-l. Young. Pinang. From Dr. Cantor's Collection. 



m, n, 0. Half-grown. East-Indian archipelago. From the Col- 

 lection of Dr. van Lidth de Jeude. 



