38 PERCY SLADEN TRUST EXPEDITION 



Family MegachilidaB. Subfamily LithurginsB. 

 LiTHUJiGUS Berthold. 

 10. Ldthurgus scotti, sp. nov. 



Length, $ about 11^, $ about 12 mm., black with hair at apex of abdomen black or 

 brownish-black. A species of the group of L. atratus Smith (India), L. atratiformis Ckll. 

 (Australia) and L. alhqfinihriatus Sichel (Tahiti) ; so close to these that only a comparative 

 description is useful. It differs from all three in having the first recurrent nervure exactly 

 meeting the first transverso-cubital. 



I possess only the male of L. atratus ; from this L. scotti male differs at once by the 

 nearly simple character of the hind tarsi. The basitarsus is distinctly curved, with its 

 apical two-fifths swollen behind, but the apex is not expanded or in any way peculiar. 

 The front and vertex in atratus are covered with black hair, while in scotti the fi^ont is 

 clothed with pale ochreous (a few dark hairs intermixed in the region between the 

 antennae), while that of the vertex is mixed black and dull pale ochreous. In atratus 

 the white bands of the abdomen are conspicuous above and beneath ; in scotti they are 

 reduced, and not so white, though quite evident toward the sides of the dorsal segments. 

 In atratus the margmal cell is much more sharply pointed, and the second submarginal is 

 much longer in proportion to its height. 



Compared with female L. atratiformis, the female scotti is at once distinguished by 

 the wholly pale (creamy-white) hair of pleura (it is black in atratiformis), but by the 

 venation and other characters it is very closely allied. 



Compared with female L. alhofimhriatus, it is noted that the hair of the lower part 

 of the cheeks is strongly mixed with black in alhofimhriatus, while it is all pale yellowish 

 in scotti. In both, the lower margin of the clypeus is bearded with shining orange hair. 

 The hind legs of male alhofimhriatus are formed practically as in scotti. The hair of the 

 mesothorax and scutellum in male alhofimhriatus is black, but in scotti it is greyish-white, 

 mixed with black on scutellum. In female L. alhofimhriatus the sujDraclypeal area is 

 prominently keeled, but in scotti there is a raised smooth line, hardly a keel. 



Locality. Mahe, Seychelles, one of each sex (ZT. Scott). The male is from Cascade 

 Estate, 800 — 1000 ft. ; the female fi'om Anonyme Island, January 1909. 



This is evidently quite distinct from L. illudens Sauss., from Madagascar. I have 

 L. alhofimhriatus not only from Tahiti, but also from the Hawaiian Islands, whence I 

 have received both sexes from Dr Perkins, with the statement that it was introduced 

 about 1899. 



It may be worth while to remark that the differences given by Bingham (Fauna 

 Brit. India) to separate L. atratus from L. dentvpes are mainly sexual. L. dentipes was 

 based on a male from Australia ; it can be distinguished from the male of L. atratiform,is 

 by the colour of the pubescence. 



The Lithurgus of Christmas Island (Z. andreivsi Ckll.) is very distinct from 

 L. scotti. 



