the Genus Monochirus. 407 



in length, all presenting similar variegated markings. The 

 colour of the upper side of Hanmer's fish is described to be 

 " a very light brown tinged with red," and is figured of a 

 uniform colour. Such Dr. Parnell's (preserved dry) likewise 

 are, becoming darker at the margin, over which the black 

 blotches on the dorsal and anal fins occasionally extend for a 

 few lines : this marking, as represented in Hanmer's figure, 

 is characteristic of that in the specimens at present under ex- 

 amination ; but these exhibit rather more black on the dorsal 

 fin. Hanmer's specimen was 6| inches long, Dr. Parnell's 

 are 7i and 8| inches. 



The number of denticles and form of the scales of the Mono- 

 chiri will not prove to be a positive character, though, relatively 

 considered, they may be of service in the elucidation of species. 

 On examining one of my specimens of M. linguatulus as to 

 the number of these denticles, I found that a scale taken from 

 the lateral line had 21 ; another from the next row had 22 

 and 2 rudimentary points ; a third from an adjacent part of 

 the body had likewise 22. The outline of these scales was 

 different, the first being conspicuously contracted about the 

 middle at one side, and straight throughout the other ; the 

 second slightly contracted about the middle on both sides, 

 and the third with the sides quite straight. In each of two 

 scales taken from the lateral line of Dr. Parnell's specimen of 

 M. minutus there are 22 large strong denticles, with rudi- 

 mentary points between them : outline of these scales differ- 

 ent, and as in the individual just described. In my specimen 

 of M. variegatus, two scales which touched upon the lateral 

 line exhibited only 10 and 13 points; but this paucity may 

 be owing to its diminutive size. A scale from the lateral line 

 of Dr. Parnell's smaller specimen of the Red-backed Flounder 

 exhibited 19 denticles, one off the third row from it 18. The 

 form of scale in all the individuals examined is much the 

 same, being broader for its length than that of scales I took 

 from Solea vulgaris ; they were generally, but not always, con- 

 tracted about the middle, either at one or both sides. The 

 scales were all examined separately under the microscope, and 

 hence is a different result in the number of denticles from 

 what would have appeared, had they been reckoned on the 

 body of the fish. 



