Records of Bees. 663 



the coarser, oblique rugge at base of metathorax, and the 

 broad eutire hair-bands of the narrower abdomen. It is 

 structurally closer to H. leucozonius, from which it is at once 

 known by the dark basitarsi. In the North American 

 fauna it may be compared with H. trizunatus, from which it 

 differs by the much more closely punctured mesothorax and 

 the much stronger rugse of basal area of metathorax. 

 H. horishensis is not represented in the Sauter collection 

 from Formosa. 



The following table separates the females of four Formosan 

 species of Halidus, and contrasts them with a number of 

 forms which they more or less closely resemble : — 



Sides of prothorax above much enlarged, 

 concave, produced to an acute angle ; 

 mesothorax witli very strong well-sepa- 

 rated punctures ; abdomeu closely, very 

 mmutely punctured. (Formosa.) peratif/iilatiis, Cldl. 



Prothorax normal, or only moderately pro- 

 duced at sides 1. 



1. Middle and hind tibiae and tarsi clear fer- 



ruginous ; basal bands of second and third 

 abdominal segments extremely broad at 

 sides, but narrowed almost or quite to a 

 point in middle ; tegulaj bright ferrugi- 

 nous; mesothorax sparsely punctured. 



(Samarkand.) eqi(estris, Morawitz. 



Middle and hind tibiae and tarsi not thus 

 red (tarsi in trizonatus sometimes partly 

 reddened) 2. 



2. Basal area of metathorax finely granular 



(finely striate in manitouellus) ; meso- 

 thorax very finely punctured 8. 



Basal area of metathorax conspicuously 

 ridged, wrinkled, plicate or striate (finely 

 striate in manitouellus) 5. 



3. Basal bauds of abdomeu pale fulvous, on 



second and third segments strongly nar- 

 rowed in middle ; wings dusky greyish. 



(Colorado.) manitouelhis, Ckll. 



Basal bands of abdomen cream-colour, not 

 narrowed in middle (except that on second 

 moderately so in trizonatus) 4. 



4. Wings very strongly reddened. (Mexico.) schcnckii, Ritsema. 

 Wings little reddened. (Colorado.) trizonatus, Cresson. 



6. Hind margins of abdominal segments fer- 

 ruginous or pallid. (Europe.) ca/cea<Ms (Scop.). 



Hiud margins of abdominal segments 

 black 6. 



6. Bands at bases of second and third abdo- 

 minal segments much narrowed in middle, 

 or interrupted, and always yellowish- 

 tinted or fulvous 7. 



