62 



INSECTS OF SAMOA. 



panying minor differences in this organ 



Text-figs. 10-17. — Fig. 10, B. conviva Stal, 

 Ceram, left clasper (Xth segment) ; fig. 11, 

 B. exhausta Guer., type of D. parabola 

 Walk., left clasper (Xth segment) ; fig. 12, 

 B. exhausta Guer., (example from W. Buru 

 with venation of B. conviva), left clasper 

 (Xth segment) ; fig. 13, B. exhausta Guer., 

 (example from W. Burn with normal 

 venation), left clasper (Xth segment) ; 

 fig. 14, B. exhausta Guer., from Samoa, left 

 clasper (Xth segment) ; fig. 15, B. exhausta 

 Guer., (another specimen from Samoa, 

 Apia), left clasper (Xth segment) ; fig. 

 16, B. exhausta Guer., (still another speci- 

 men from Samoa, Apia), left clasper 

 (Xth segment) ; fig. 17, 5. exhausta Guer., 

 Samoan example (Savaii), left clasper 

 (Xth segment). : 



and in the shape of the claspers. On the 

 basis of macroscopic and microscopic 

 characters it is evident that we are deal- 

 ing with one polymorphic form, com- 

 parable with Metrosideros villosa auctt. 

 among the Pacific Myrtacae. To settle 

 the question it will be necessary firstly, 

 of course, to examine the respective 

 types, and secondly to study series 

 from the different islands comparable 

 with the extensive one from Samoa 

 that I have been privileged to ex- 

 amine. It seems to me very likely 

 that material from more numerous 

 intermediate stations would yield still 

 more annectent examples than we have 

 at present. In the meantime B. conviva 

 is kept doubtfully distinct, and the 

 Samoan forms are regarded as belonging 

 to B. exhausta. To show more funda- 

 mental variation in genitalia in the 

 genus, the aedeagus of an undoubtedly 

 distinct species, B. famulus Dist., is 

 represented in fig. 18. 



The type of Cicada hastipemiis 

 Walk, is a female which agrees specifi- 

 cally with D. parabola, and thus pre- 

 sumably with B. exhausta* 



The nymph of Baeturia exhausta. 

 — As pointed out on other occasions, 

 the last nymphal exuviae of cicadas 

 make beautiful objects of study. In 

 the present species the antennae have 

 9 segments, including a very minute 



* In view of the above discussion, the Baetuna species of Buru are of the greatest interest. 

 Schmidt {Treubia, 7, p. 222, 1926) records from the island in question B. conviva, B. exhausta, 



