186 



INSECTS OF SAMOA. 



There are sixty-two specimens of this species in the present collection, and, 

 together with the four, including the types, sent by Dr. Walther Horn, I have 

 examined sixty-six examples. 



In view of the small amount of variation shown by so much material, I 

 cannot help coming to the conclusion that S. annulipes Wse. should be con- 

 sidered as a variety of S. cauta Wse. ; thus the former name becomes a synonym 

 of the latter. 



Variation. — The variation in size is considerable. It will be noticed that 

 there is a difference of 1 mm. in length between Weise's type and cotype, and 

 there are examples before me which are as small as 4 mm. There is a corre- 

 sponding apparent variation in shape in which the body is slightly narrowed 

 towards the apex. If a single small example is captured and compared with 

 the type there will be considerable doubt as to whether it belongs to the same 

 species. 



The variation in colour and markings have already been indicated in 

 the short colour diagnosis above. There is more structural variation in the 

 sculpturing of the head than elsewhere. The confluence of punctures in the 

 interantennal producing a rugosity, is variable. 



5. Stygnobia variabilis, sp. nov. (Text-fig. 5). 



Body ovate. General colour shining dark brown ; in uniformly dark brown 

 examples, pronotum and thoracic sterna often darker than rest of body. The 

 colour varieties are as follows : vertex of head may have a longitudinal stripe, 

 broad at base, narrowing towards mouth-parts. Elytra in many examples 

 with a broad stripe along suture, covering a considerable area on each side, and 

 about middle sending off an arm on each side, which encircles a convex area at 

 base (in some examples this encircling process is incomplete) ; on apical area 

 sutural stripe broadening considerably, covering in an ill-defined manner a large 

 area on each elytron. In some examples the sutural stripe ends abruptly about 

 the middle, but the black colour on the apical area is nevertheless present, and 

 continuing forwards forms a longitudinal stripe. In the specimens with the 

 elytral markings the pronotum may be completely black, or may have certain 

 areas at the sides brown and the rest black, while the lateral edges of the elytra 

 are often black. Among the patterned specimens, the tibiae diffusedly and 

 the hind femora at the point of articulation are often black. Some examples 



