1918.] F. H. Gravely : Passalidae of the World. 69 



suture, no tubercles being developed in this position in specimens from Africa. Kuwert 

 has, it is true, described from Madagascar one species of each of his otherwise purely African 

 genera Erionomus and Didimoides ; but it remains to be seen whether he was right. In 

 the case of the former genus the sentence " Der ganze Clypeus in der Breite der ganzen 

 Oberlippe scharf vorgezogen " suggests, for instance, that studi may belong in reality 

 to the new genus Malagasalus, established below to receive the only species of 

 .Solenocyclinae known to me in which the clypeus is exposed, and the pair of marginal 

 tubercles most characteristic of the family as a whole — i.e., those immediately above the 

 lateral extremities of the clypeus — are entirely absent. 



None of the Malagasy genera hitherto described contain very many species ; and the 

 •differences between them may advantageously I think be regarded as specific rather than 

 generic. I propose, therefore, to unite all of them under the name Solenocyclus. 



Some of the African genera appear to be decidedly larger ; but in spite of this I am 

 unable to find satisfactory characters by which to define more than two. I propose, 

 therefore, to unite under the name Pentalobus, Kaup, all species with hairy sides to the 

 metasternum and a more or less distinct tubercle or pair of tubercles or excavation in 

 the middle of the anterior margin of the head ; and to unite under the name Erionomus» 

 Kaup, all species in which the sides of the metasternum are hairless and the middle of the 

 .anterior margin of the head is straight. 



The genera of Solenocyclinae may now be defined as follows : — 



f A more or less distinct pair of marginal tubercles present imme- 

 i diately on tlie inner side of the fronto -vertical sutures (Mala- 

 J gasy forms) 



( Tubercles not present in this position (African forms) 

 ( The clypeus exposed 

 - 1 ) The clypeus hidden 



The sides of the metasternum hairless ; the anterior margin of 

 the head more or less distinctly notched in the middle line, 

 or with a median tubercle 

 The sides of the metasternum hairy ; the anterior margin of 

 the head without any median notch or tubercle 



Genus MALAGASALUS, n. gen. 



Type, Malagasalus clypeatus, n. sp. 



The clypeus exposed ; a pair of marginal tubercles present immediately on the inner 

 side of the fronto-vertical sutures ; the sides of the metasternum hairless. 



Malagasalus clypeatus, n. sp. 



Fig. VIII, 1, p. 70. 



Two specimens from Fenerive, Madagascar. Length 34 mm. 



The antennae each have three well developed lamellae. The labrum is concave in 

 iront, convex at the sides, slightly narrower behind than in front. The central tubercle 

 is strongly elevated above the short parietal ridges, but is somewhat obtuse. The frontal 

 ïidges diverge from it in an angle of about 90° ; they extend to the strongly developed 



. . 



2. 





3. 



Malagasalus, p. 69. 





Solenocyclus, p. 70. 





Pentalobus, p. 72. 





Erionomus, p. 74. 





