SCIENCE-GOSSIP. 



except in North America. Another numerously repre- 

 sentet' genus is Paniassiiis, but with only three species 

 in Europe. It is rich in specific forms on the elevated 

 plateaux and mountains of Xorthem and Central Asia, 

 China and the Himalayas. Several species also occur in 

 the Califomian mountains. It is thought that this genus 

 originated in Central .\sia, spreading^ thence eastward 

 and westward, so that it may be said to be particularly 

 characteristic of the I'alaearctic Region ; it is repre- 

 sented in all the sub-regions. Some genera are 

 absolutely peculiar to the region, .\mong these may be 

 noticed Hyptrmneslra represented by a single species 

 having somewhat the aspect of a I'ariiassius. It is 

 confined to the Eremian sub-iegion, inhabiting 

 abundantly the deserts to the east of the Caspian. 



The genus Thais is remarkable in Iwing confined 

 to those portions of Europe, -Asia and Africa, which 

 are in proximity to the Mediterranean. The species 

 of thLs genus are extraordinarily different from any 

 other butterflies, and do not occur in other parts of 

 the world. One well-marked aberration of a species of 

 Thais is absolutely localized in the neighbourhood of 

 Digne in Provence and has never l)ecn found any- 

 M here else. This is Thais medesicasK ich. hoiwralii. 

 Dorilis is a genus of limited distribution, occurring 

 only in Asia Minor, Syria and the Greek Islands. 

 ThaUropis, a peculiar genus allied to Apattira, is 

 confined to .\sia Minor. Among the Pieridae, the 

 central .\sian genus Mesapia is exclusively Palaearctic, 

 as are also Thestor and Laeosopis in the Lycoitiidae, 

 Polycaata in the Erycinidae, and Mclanargia, and 

 Triphysa in the Satyridae. 



Distribution ok Species. 



As regards the distribution of specific forms, it is 

 only natural that the most widely distributed genera 

 should exhibit the greatest diversity of species. 

 Having regard to the varying physical conditions of 

 the Region it is not surprising that many species are 

 circumscribed and local in their habitats. .Some, 

 however, are distributed more or less throughout the 

 Territory, being capable of adapting themselves to 

 various and diverse conditions, while the former do not 

 appear to have this aptitude. Two species are found 

 in every pan of the Palaearctic Region where Butter- 

 flies occur. These are lx)th members of the family 

 Lycaenidae Theula ruhi (the green-hair-streak), and 

 I'olyommalus phlaeas (the small-copper). 



The follow ing species inhabit the entire region, with 

 the exception of sub-region I. */'api/io mathaon 

 Iswallow-tail) : .-//orjVz cra/a<f» (black -veined white), 

 Pi'eris hrassicae (large white), /'. rapae (small white), 

 /'. daplidiec (green-chequered white). Rhodocera 

 rhaiinii (brimstone), Ly^acita astrarihc (brown argus), 

 /,. icarus (common blue), L. an^ioltis (azure blue), 

 t'antssa 'urticac (.small tortoLseshell), /'. cardui 

 (paintcfl XaAs),' Argynnis a,^aia (dark green fritillar)')< 

 'Argynnis niohe, Coenonympha * patiiphilus (small 

 heath), Hesptria *lineola, * H. {omnia (pearl skipper). 

 Those marked * do not orcur in the Canaries, and 

 Ar^-miit niohe is proViably absent from Britain, but 

 I'anessa urtitae dtjes occur in sub-rej^ion I. in the 

 form of its var. polaris, and it is po.ssible V. cardui 

 also, as il L-. an almost cosmopolitan s|)ecies. 



At least six species are limited to the Polar regions, 

 viz., Colias nastes, C. atilhyale, C. hecia, Argj'iiiiis 

 polaris and A. chariclea ; these are all circumpolar, in- 

 habiting the Polar Regions of Europe, Asia and 

 .\mcrica, Argy'tinis improba Bute, is peculiar to 

 Nova Zembla. 



In islands there is always a tendency towards the 

 formation of a fauna peculiar to themselves. This 

 is shown to some degree in the Lepidoptera of the 

 British Isles, more especially among the Heterocera, 

 and in them most markedly in Scotland and Ireland. 

 There are several instances of insularity among British 

 Butterflies. Our form of Aulhocharis lardamines 

 differs from that usually found on the continent ; 

 Polyommaltis dispar, unhappily now extinct, was 

 peculiar to England, being represented on the con- 

 tinent only by the var. rutilus. Lycaena aslrarche var. 

 arlaxerxcs only occurs in Scotland, and the var. 

 salmacis is peculiar to northern England. To these 

 may be added Melitaia aiirinia var. hihirnica Birchall 

 and Coenonympha tiphon \^x. laidion Bkh., both of 

 which forms are peculiar to Ireland. 



The islands of Corsica and Sardinia possess the 

 following species and varieties peculiar to them- 

 selves : — Papilio hospiton Gn., Anthocharis lagis var. 

 insularis Slg., Vanessa iehmisa Bon., Argj'nnis 

 elisa Godt., Salyriis neomiris Godt., S. semele var. 

 arislaeus Bon.. Epinephele mirag Ghil. , Parargc 

 tigelliiis Bon., Coenonympha eorinna Hb. (pel haps 

 occurring in Sicily), Syrichthiis sao var. therapne Rbr. 



The following are peculiar to the Canaries ; — 

 Picris eheiranthi, P. woliastoni, Lycaena ivehhiana, 

 Khodocera cleobule and Pararge xiphioides. 



Whilst on tVe subject of " insularity,"' we may 

 notice the tendency to be obsen-ed on islands towards 

 a paucity of specific forms ; consequent, no doubt, 

 upon being isolated from the mainland, and therefore 

 cut off' from recruiting sources. There is no doubt 

 that Papilio podaliriiis, Polyomma/ns ''irgaiireae and 

 hippothoe. Argynnis dia and Lycaena seiiiiargus were 

 truly British insects a century ago. I'olyommatus 

 dispar has become extinct within the memory of those 

 now living; and the next generation may have to 

 bewail the loss of Aporia cralaegi, once a widely 

 distributed species. It is doubtful whether it 

 exists at the present moment in any British locality. 

 I.imenilis sihilla, once described as "common in 

 ever)' wood," is now restricted' to the New Forest, 

 and one or two other localities in the south, aiid will 

 probably in another half centur)- be a stranger to the 

 British Fauna. The same future may also be pre- 

 dicted for Lycaena arion, Melitaea cinxia, and 

 perhaps even M. alhalia and Apalura iris. 



With facts .such as these in mind, we cease to 

 wonder at the absence in Britain of so many species 

 that are to \k met with commonly in the immediately 

 adjacent Continental districts. If we travel eastward 

 from L<jndon, to no greater distance than Penzance 

 wouUl Ix', had we taken a w esterly direction, we should 

 find ourselves in Belgium ; where many species of 

 butterflies are common that are not met with in 

 England, or else are very rare. Entomologists had 



