1894. SCORPIONS. 357 



safely adopt the boundaries that are usually recognised as separating 

 the Palaearctic and Oriental Regions. 



The exact limits between the Palaearctic and Ethiopian are also 

 a little uncertain. Mr. Wallace draws the line of demarcation along 

 the tropic of Cancer, and thus refers the northern half of Arabia to 

 the former and the southern to the latter. But, with two excep- 

 tions, the Scorpions that occur at Aden, and at other parts of South 

 Arabia, are either identical with Syrian and Egyptian forms, or are 

 very nearly related to them. For instance, Nebo, which is met with 

 at Aden and Muscat, is only known elsewhere from Syria and Egypt ; 

 Hemiscorpius has been obtained at Aden and Baghdad; Biiihus 

 qiiinqne-stnatus, a common Egyptian species, extends to Perim Island 

 and South Arabia, and the Algerian and Egyptian Prionurus 

 australis has been received from Muscat. On the other hand, 

 the only Ethiopian types which are found in South Arabia are 

 a species of Scorpio and Parabuthus liosoma, which ranges from 

 Egypt to Masai-land. Clearly, therefore, the Mediterranean element 

 in South Arabia far surpasses the Ethiopian, and the whole of this 

 country must consequently be looked upon as part of the Palaearctic 

 Region. In x\frica it is impossible to draw a hard and fast line until 

 more collecting has been done. We know nothing of the species 

 which presumably inhabit the vast tract lying between Abyssinia on 

 the east and Senegambia and Guinea on the west. On the west 

 coast of the Red Sea, however, the Mediterranean element is 

 represented at Massowah and at Zaila, in Somali-land, by a variety 

 of the Spanish and North African Biithns europatis ; but species of the 

 essentially Ethiopian genus Scorpio extend into Nubia and Abyssinia. 

 A similar partial overlapping of the two faunas occurs on the West 

 Coast of North Africa, namely, in Senegambia, which is the northern 

 limit of Scorpio, and the southern limit of Buthus eiiropaiis and Prionurus 

 australis. We may, therefore, draw the line between these two regions 

 along the 15th parallel or thereabouts. 



The following is a list of the Palaearctic genera with the known 

 range of each. Those that are peculiar to the region are marked with 

 an asterisk : — '■'■'- Heteromeirus, two species. North Africa, Syria ; "^'Nebo, 

 two or three species, Syria, Egypt, and Aden ; * Hemiscorpius, Baghdad, 

 Aden ; '■"'lunis, one species, Greece, Asia Minor, Egypt ; ■■Belisarius, 

 one species, Pyrenees; ■'Eiiscorpius, many species, Spain and Algeria 

 to Asia Minor; ■•Prionurus, two species. North Africa to Persia and 

 Arabia ; Buthus, many species, North Africa, South Europe, Persia to 

 Pekin ; ■'■'Butheolus, two species, Sicily, Arabia, Persia ; Parabuthus, one 

 species, Egypt, Arabia. 



The Ethiopian Region is very rich in Scorpions, and contains a 

 large number of peculiar genera. It embraces Africa south of the 

 15th parallel, and Madagascar, the two areas representing distinct 

 sub-regions. The African sub-region is peopled with Scorpionidae, 

 Ischnuridae, and Buthidae. The following is a list of the genera -.-^ 



