722 MR. E, A. ELLIOTT ON THE 



incrassate, bidentate, smooth and shining, with diffuse setiferous 

 punctures : tibite as long as femora, compressed to about middle ; 

 tarsi three -jointed in both sexes. 



Black, with a tendency to brownish, especially in the cheeks 

 and tarsi. Antennae ferruginous in 5 ; black in c5' . Wings 

 hyaline. 



In (S the rugosity of the semiannular is more pronounced 

 than the punctui-ation ; the lateral lobes of the scutellum are 

 more rugose than punctate ; the abdomien is longer and more 

 slender in $ . 



Length 5 , 21-24 mm.; abdomen 16-18 mm. ; petiole 10-11 J 

 mm. ; terebra 20-22 mm. ; d , 21 mm. 



Habitat : Aden ; Ruaha River, late German East Africa. 



This species appears to differ from S. gigas Schlett. in the 

 formation of the prothorax and in the strikingly incrassate hind 

 femora. 



In some respects it resembles S. pachylomerus Schlett., from 

 which it may be distinguished by the coarsely punctate temples, 

 formation of the prothorax, and by the shorter petiole and 

 terebra. 



It resembles S. antinorii in size, length of terebra, and incras- 

 sate hind femora — this last is not uncommon among the African 

 species. It differs in the longitudinal occipital sulcus, structure 

 and sculpture of prothorax, formation of mesothorax and 

 sculpture of mesopleurfe. 



8. tihiator S is distinguished from all others yet known by the 

 hind tarsi being three-jointed, and is the only known exception 

 to the rule, that the males of this family have those tarsi five- 

 jointed. 



8. serratoi- $ alone has the hind tarsi five-jointed, otherwise 

 they are invariably three-jointed. 



5. NiGRiCAUDA Sichel. 



Megischus nigricauda Sichel (2), p. 479, $ . Ste2Jliaims n. 

 Schlett., p. 106, $ . 



2 . Frons eoriaceo-granulaxe, vertex arcuate rugose ; occiput 

 with basal third trans-striate, remainder smooth polished. Pro- 

 notum smooth and shining, neck subquadrate ; mesonotum 

 almost impunctate, smooth and shining; with an anterior 

 longitudinal impression, separated from the smooth polished 

 scutellum by a row of punctures ; median segment scrobicuJate 

 reticulate. Petiole finely trans-striate, remainder of abdomen 

 smooth polished. Terebra as long as body, sheaths black. Legs, 

 especially the hind ones, smooth and shining ; hind femora 

 bidentate. 



Black ; head red, vertex black, cheeks pale marked ; mandibles 

 basally and two or three basal antennal joints red or rufescent ; 

 anterior tarsi rufous, middle tarsi white-banded, base of hind 



