268 Insecta. 



879) Bolivar, I. and Ferrifere, C, Orthoptera, Phasmidae of the Sey- 

 chelles. In: Trans. Linn. Soc. London, (ser. 2, Zool.), Bd. XV, Heft 2, S. 293 

 bis 300, 2 Textfig., 1912. 



7 species of Phasmidae were brought from the Seychelles by the Percy 

 Sladen Trust Exp., and 3 others have been recorded. The fauna is strongly 

 Indo-Australian in its affinities, and does not include a Single representative of 

 the Phasmidae of East Africa or Madagascar. It contains 4 species of Phyllium, 

 all widely distributed in the East, while the genus as a whole is Indo-Australian, 

 with Mauritius and Seychelles as the Westernmost points of its ränge. 4 new 

 species of Carausius were found in the Seychelles: this genus is Indo-Australian 

 with its centre of distribution in the Malay Archipelago; the 4 Seychelles species 

 form a somewhat isolated group within the genus, and are the only represen- 

 tatives of the Lonchodini found outside the Oriental and Australasian regions. A 

 new species of Grae/fea was discovered: this is very remote from the centre of 

 distribution of the genus, which was previously only known from Australia, Fiji, 

 New Guinea etc. The 5 peculiar species {Carausius and Graeffcd) were all found 

 in the endemic forests, while Phyllium bioculatum was found among imported plants. 



H. Scott (Cambridge). 



880) Boliyar, I., Orthoptera: Acry diidae, Phasgonuridae, Gryllidae [of 

 the Seychelles etc.]. In: Trans. Linn. Soc. London, (ser. 2, Zool.), Bd. XV, 

 Heft 2, S. 263—292, Taf. 13, 14, 1912. 



This paper deals with the saltatorial Orthoptera of the Islands of the 

 West Indian Ocean, collected by the Percy Sladen Trust Exp. The author states 

 that the collection, which is of very special interest, shows a great difference 

 between the fauna of the Seychelles, Chagos, and Amirantes on the one hand, 

 and that of Aldabra and the neighbouring Islands on the other. In Aldabra there 

 is a decided African dement, in addition to certain forms which are at the same 

 time Asiatic and African; all these species are winged, and some are very widely 

 distributed: certain forms previously undescribed were also found in Aldabra. 

 The fauna of the Seychelles is much more original, containing no less than 9 new 

 genera (some of which are highly peculiar) and 20 new species. The fauna of 

 the Chagos also appears very special: it is connected with that of the Seychelles 

 by a remarkable new apterous genus of Gryllidae, represented by 2 species, one 

 in each group of Islands. This connection between the fauna of low coral-islands 

 (the Chagos) and that of the granitic mountains of the Seychelles ^vith their 

 highly peculiar endemic forests is very remarkable. Judging from the collection, 

 the fauna of all these islands considered as a whole contains an Africano-Indian 

 element, and very numerous peculiar forms. H. Scott (Cambridge). 



881) Brilldley, H. H., The proportions of the sexes in Forficula auri- 

 cularia. In: Proc. Cambr. Phil. Soc, Bd. XVI, Heft 8, S. 674-679, 1912. 



In the course of a long inquiry into the Variation in length of the ^ for- 

 ceps, the writer has received collections (consisting of from about 100 to over 

 3000 individuals) of this species, from a large number of different localities in 

 Britain, including some small islands off the coast. The numbers of cT and ? have 

 been noted, and the proportions are shown in a table (p. 675). The percentage 

 of ^ varies from 16,1 to 59,7. The enquiry is being continued, but so far results 

 show that (I) the proportions of <S and $ differ considerably in different loca- 

 lities in the same year, being sometimes very different in localities very close to 

 one another; (II) proportion of cf and ? may differ appreciably in the same loca- 



