704 MR. W. L. DISTANT ON AFRICAN LEriDOPTERA. [Nov. 18, 



bluish white and abbreviated ; the transverse blue fascia of lower 

 wings much narrowed and white. 



Exp. wings 4 inches. 



Hab. Magila, East Africa. 



In structure resembling the 2 of D. salmacis, Dr. 



Diadema dinarba, Hew. Ex. Butt. iii. Diad. t. 2. f. 7 (1865). 



This species seems subject to extreme variation, and, as far as I 

 have been able to examine specimens, appears under the following 

 forms : — 



Var. a. Typical. Hew. ib. 



Var. b. Fore wings with transverse spots much enlarged, almost 

 reaching row of submarginal spots. Hind wings with basal white 

 portion enlarged, and almost occupying half of wing. 



Var. c. Fore wings with transverse spots enlarged and fused, oc- 

 cupying the whole discal portion of the wing, and merging with 

 submarginal row of spots, some of which are absorbed. Hind wings 

 with the basal white portion now increased till it occupies all the 

 wings but a broad outer margin. 



Var. d. Both wings almost wholly white. The dark portions of 

 the previous varieties only indicated, and the submarginal row of 

 spots almost obliterated. 



Hab. Vars. a, b, d, Calabar ; var. c, Sierra Leone. 



It will be thus seen that variation exteuds from the melanic form, 

 a, through gradually increasing albinism, till the extreme form, d, 

 is reached ; or, of course, vice versa from d to a. Besides which, 

 though these typical varieties are indicated, there are numerous inter- 

 mediate forms which destroy their value as to constancy. Similar 

 variation may be seen in another African species of the genus, 

 J), dubium, Beauv., some of the forms of which are regarded by 

 competent lepidopterists as specific. 



Paradiadema, gen. nov. 



Allied to Diadema, from which it differs in the hind margin of 

 the fore wings being scarcely excavated, and the apical angle of the 

 same, which is only faintly prominent ; lower subcostal nervules 

 emitted nearer apical margin ; costa of hind wings more arched, 

 precostal nervure curved outwardly. 



Paradiadema hora, n. sp. (Plate LIV. fig. 1.) 

 c? . Above ferruginous. Fore wings crossed by a transverse 

 white fascia, commencing near costa a little beyond end of cell, 

 and terminating a little below centre of hind margin ; this fascia 

 is straightened outwardly, but inwardly, near end of cell, deeply 

 toothed ; interior of cell bluish black, with four or five white spots, 

 outer one somewhat linear and perpendicular. Hind wings crossed 

 by a broad yellowish-white fascia toothed outwardly, and widened 

 towards inner margin. Underside much paler in colour, fasciae as 

 above ; cell of fore wings with the white spots bordered with black, 

 a black spot near base, and two irregularly waved black lines, situated 



