256 Mr. G. J. Arrow on Sexual Vimoiyhism in 



The first case of sexual disparity of claw-structure was 

 noticed by Mr. Gahan, who described a species in 1896 

 under the name of Anomala rgrcgia in which the outer 

 claws of the first two pairs of legs are cleft in the female, 

 while in the male they are quite simple ; and Herr Kolbe 

 has since described the representative of another group 

 exemplifying a similar interesting phenomenon. In this 

 also the female has the claws of the first two pairs of 

 legs divided, which is the most prevalent condition in the 

 genus, but the male has those of the first pair only divided. 

 Of each of these conditions I shall record additional 

 examples, and also describe the representative of a third 

 condition in which the female has the claw of the front 

 tarsus only divided and the male all the claws undivided. 



Belonging to the cgrcgia group is A. kcrstcni, Gerst., in 

 which, although it has liitherto been overlooked, the claws 

 are all simple in the male sex, while in the female they 

 are of the typical structure. Of a series of eleven specimens 

 in the British Museum, from Somaliland, Masailand and 

 British East Africa, two are males. 



To these two species I propose to add a third belonging 

 to the same group. 



A. (lisjmrilis, sp. n. 



A. Eijyecjise et kerstenl aftinis: elongata, cyliiulrica, nitida, flavotesta- 

 cea, tibiis tarsisque rufis ; clypeo quadrato fere emarginato, margine 

 valde reflexo, tenuiter punctato ; prothorace transverse, polito, luiiui- 

 tis sime punctato ; elytris fortiter punctato-striatis. Long. 17 mm. 



(J. Unguiculis omnibus simplicibus, clypeo testaceo, margine 

 nigro. 



9 . Pedum anteriorum et mediorum unguiculis externis fissis, 

 corpore magis robusto, prothorace breviore, clypeo infuscato. 



Hah. Lagos. 



This is smaller and more shining than either of the 

 allied species and differs conspicuously by the form of the 

 clypeus, which is straight and angular with the margin 

 sharply reflexed, as in Burmeister's section Hcter&plia. 

 The prothorax is transverse, but less so in the male than 

 in the female, and is very finely and distantly punctured. 

 The elytra are coarsely punctate-striate with the intervals 

 uniformly finely punctured. The pygidium is coarsely 

 punctured. 



