of the Genus Tcracolii.s, Sicnins. 387 



is notewoitliy tliat the Arabian T. ]t1nsailii has a male of the 

 wet-season jthase and a female of the dry type ; also that the 

 nearly allied T. jnuVaris ocenrs at Karaehi with males both 

 of the >vet and dry phases, but females of the dry phase onl)'. 



Another point whieh proves tlie seasonal character of these 

 diftt-rcnt variations, wherever seasons can be said to exist, is 

 that an uimsually wet country invariably increases the wet 

 characteristics, and an unusually dry country has the same 

 eftVct upon the dry type of the species ; thus the dry form of 

 2\ suhfasctatus from the Nyasa-'ranganyii<a plateau, where 

 the country is almost a desert in the dry season (though 

 extremely moist during the rains), is much more emphasized 

 than it is in southern South Africa, so much so that it was 

 described as a dillcrent species. 



Jn the spring of J 89(5 Mr. Guy A. K. Marsliall, one of the 

 most painstaking and indefatigable collectors who has visited 

 the so-called " Dark Continent," came to the Museum witli 

 the view of a])plying the exj)erience gained by him in 

 ^lashunaland to the magnificent collection under my charge. 

 Finding how rich we were in both examples and species of 

 the genus Teracolus, and observing that the wet and dry forms 

 were at that time kept separate as distinct species, Mr. .Marshall 

 made uji his mind to thoroughly revise the synonymy of the 

 genus. Had he waited until 1 had rearranged our material, 

 ■which was cumbered by masses of only half-determined, 

 specimens (so crowded together that the labels could with 

 difficuliy be distinguished), he might have produced a really 

 satisfactory memoir. As, however, he elected to go to work 

 U} on the genus in its crowded condition, it is not surprising 

 that his synonymic work is not only more or less overdone, 

 but in some cases confounds species appertaining to widely 

 distinct grou])S. At the same time much that Mr. Marshall 

 has suggested in his pa])er (Proc. Zool. Soe. 1897) is undoubt- 

 edly correct, and perhaps the fact that the work of this reviser 

 calls loudly for revision in certain points may have been 

 beneficial as inciting me to especial care in studying the sexes 

 and seasonal forms, with due regard to the geographical 

 range of each species, in order that 1 might not only straighten 

 out the inequalities which certainly exist, but avoid the error 

 of making confusion worse confounded. How far I have' 

 succeeded iuture students of the genus will have to decide. 

 ]t is probable that some forms which 1 have not seen any 

 justitication for suppressing may yet prove not to be good 

 species, and it may be that in one or two cases I may, like 

 my friend Mr. Marshall, have gone a little too far. 



