8. DIAORAMMA. 335 



and form, with the other shorter ones, a rounded margin. One-half 

 of the tin is thickly covered with scales. The pectoral is slightly 

 rounded, and its length 65 in the total. The ventral is rather shorter ; 

 its base falls immediately behind that of the pectoral ; the spine is 

 moderate, about two-thirds the length of the fin. Both the latter 

 fins are far distant from the vent. 



The scales are ratlier small, ctenoid ; the lateral line is very slightly 

 curved. 



The teeth of the jaws are in villiform bands, the outer row con- 

 taining rather larger ones. 



The coloration is now brownish grey, with darker stripes, waved 

 and anastomosing ; the stripes have a more longitudinal direction on 

 the anterior part of the body, and a more oblique one in the middle 

 and posteriorly. There are three indistinct bands across the oper- 

 culum. 



inches, lines. 



Total length 11 2 



Height of the body 3 5 



Length of the head 2 9 



of the fourth dorsal spine 1 0| 



of the thirteenth dorsal spine .... 9 



of the eleventh dorsal ray 1 2| 



of the longest caudal ray 2 2 



of the second anal spine 1 2 



Distance between caudal and dorsal fins . . 1 

 between anal and caudal fins . . 2 



'M. Diagramma nitidum, (Plate XIX. fig. B.) 



D. ^. A. |. L. lat. 95. L. transv. 20/25. 



The height of the body is 3^ in the total length, the length of the 

 head four times. Caudalis truncated. The second anal spine 

 stronger, but scarcely longer, than the third. Eeddish brown (in 

 spirits), with six bluish, darker-edged, parallel, longitudinal bands : 

 the first from the nape to the origin of the .soft dorsal ; the second 

 from above the eye to the posterior third of the soft dorsal ; the 

 third from the eye on, and above, the lateral Hne to the back of the 

 tail ; the fourth from the eye below the lateral line to the middle of 

 the tail; the iifth from below the eye to the inferior part of the 

 caudal ; the sixth from the mouth over the root of the pectoral to 

 the end of the anal fin. 



a. Australia. Presented by the Earl of Derby. 



Description of the specimen. — The greatest dejith of the body is 

 above the pectoral fins, where it is contained 3^ in the total length ; 

 the upper profile descends parabolically from the third dorsal spine to 

 the mouth. The cleft of the mouth is horizontal and small, the 

 upper maxillary not extending to tlu^ anterior margin of the orbit. 

 The diameter of the eye is one-third of the length of the head, and 



