SCOTT— COLEOPTERA, LAMELLICORNIA AND ADEPHAGA 253 



Dytiscidae. 



Canthydrus Sharp, On Dytiscidse, p. 269. 



40. Canthydrus notula (Erichson). 



Hydrocanthus notula Erichson, Arch. Naturg., ix. 1843, i. p. 220. 



Canthydrus notula Sharp, On Dytiscidse, p. 275 ; Kolbe, Abh. Senckenb. Ges., xxvi. 

 1902, p. 574. 



Canthydrus higuttatus Regimbart, Mem. Soc. ent. Belgique, iv. 1895, p. 123, and Bull. 

 Soc. ent. France, 1900, p. 49; Alluaud, Liste Coleopt., p. 62. 



Loc. Aldabra : Takamaka, several hundred specimens, 1908 (Fryer); 1895 (Voeltz- 

 kow). Widely distributed in Tropical Africa. 



Laccophilus Leach, Zool. MiscelL, iii. 1817, p. 69. 



41. Laccophilus posticus, Aub^. 



Laccophilus posticus Aube, Spec. Hydrocanthaires, 1838, p. 428; Sharp, On Dytis- 

 cidse, p. 309; Alluaud, Liste Coleopt., p. 64; Kolbe, Abh. Senckenb. Ges., xxvi. 1902, 

 p. 573. 



A large series, about 66 specimens. In many specimens the undulating dark lines on 

 the elytra are interrupted at about ^ of the length from the apex, so that a transverse 

 pale mark, not reaching quite to the suture, is formed : there is considerable variation in 

 the development of this, in some specimens it is scarcely perceptible while in others it is 

 fairly conspicuous. Two $ in Dr Sharp's collection (Brit. Mus.) have this pale band 

 very little marked. In the $ the abdomen is pitchy-black ventrally except at the base 

 and apex, where it is reddish brown : the 6th segment has its posterior margin sinuate 

 on either side, and is produced in the middle. In the ? the abdomen is much lighter in 

 colour ventrally, being reddish-brown throughout, only slightly darker in the middle : the 

 6th segment is a little less sharply produced in the middle, its posterior margin is slightl}' 

 sinuate on either side, and there is also sometimes a very small and slight sinuation in the 

 middle. 



Loc. Aldabra: "Wilson's Well," Takamaka, x. 1908 (Fryer): 1895 (Voeltzkow). 

 Madagascar and Mauritius. 



42. Laccophilus addendus, Sharp. 



Laccophilus addendus Sharp, On Dytiscidae, p. 316 ; Alluaud, Liste Coleopt., p. 63; 

 Kolbe, Abh. Senckenb. Ges., xxvi. 1902, p. 573. 



Not obtained by the Percy Sladen Trust Expeditions. 

 Loc. Aldabra: 1895 (Voeltzkow). Madagascar. 



Hydrovatus Motschulsky, Etud. ent., 1885, p. 82. 



43. Hydrovatus humilis, Sharp. 



Hydrovatus humilis Sharp, On Dytiscidaj, p. 327 ; Regimbart, M^m. Soc. ent. 

 Belgique, iv. 1895, p. 107 ; Alluaud, Liste Coleopt., p. 60. 



