1404 Catalogue of Malayan Fishes. [Dec. 



Fam. TRYGONISIDiE. 



A. Tail without spine. 

 Gen. Rhachinotus,* Cantor. 

 (Equivalent to Anacanthus, Ehrenberg, 1837.) 

 Teeth flattened. Tail without radiated fin, but with a skinny hem 

 beneath, or naked. 



Rhachinotus africanus, (Bloch-Schneider.) 



Raja africana, Bloch-Schneider, 367. 



Anacanthus africanus, Miiller und Henle, 157. 



Above greenish white ; beneath white. Iris golden greenish ; pupil 

 triangular, black. 



Habit. — Sea of Pinang. 

 Guinea, Red Sea. 



The disk is rounded, a little narrower towards the tail than towards 

 the slightly projecting pointed snout. A space about 4 inches in 

 breadth, comprising the snout, forehead and the pectoral fins, is free 

 from scales, but sparingly covered with distant thorns. The latter, of 

 which none exceed -§- inch in height, stand erect on a rounded or oval 

 radiated base. The head from between the eyes, the back and the 

 anterior two-thirds of the tail, (the latter above and beneath,) are 

 thickly covered with small heart-shaped scales. Their surface is smooth, 

 obliquely raised towards the apex, which is generally directed inwards 

 to the mesial line of the body. Their margin is abrupt, with three or 

 four concentric lines or strata. Between the scales are scattered a num- 

 ber of single thorns, the longest of which are about T \ of an inch. 

 Their base is stellate, with three to five roots fitting into the intervals 

 between the nearest scales. The thorns are generally erect, but those 

 of the posterior part of the back and of the tail are directed slightly 

 backwards. On the upper part of the anterior fifth of the tail the 

 thorns cease. The tail is compressed, gradually tapering to a narrow 

 point, and densely covered with scales as far as the posterior third, 

 where they become few and far between. The abdominal surface of the 

 tail, as far as the thorns extend, is broad, convex ; the rest is acute and 



* 'Pdxos thornbush; vwros back. Substituted for Anacanthus, Ehrenberg, 

 1837,pre-occupied by Anacanthus, Gray, 1831, (Pise.) and Anacanthus, Serville, 

 1832, (Coleopt.) 



