XIX. OXYBELUS. 107 
of species with all the accuracy I could wish, from not 
knowing whether the characters of colour and of the form 
of the metathoracic mucro are constant. Those which I 
have described appear to be specifically distinct ; but as indi- 
viduals, in several genera of these aculeates, take a wide 
range of variation, I hesitate speaking positively until I 
shall have had the opportunity of examining numerous 
specimens. There seems to be but one common species 
in this country. 
Sp. 1. unictumis. Lin. 
niger, abdominis segmentis tribus punctis duobus albis sublate- 
ralibus, pedibus rufis. 
length 2—4 lines. 
Latr. Hist. 13. 307.2; Nouv. Dict. 24. 312 ; Fab. Piez. 316.2; Oliy. 
Ency. Méth. 8. 595. 8; V. d. Lind. pt. 2. 35. 5. 
Vespa uniglumis. Lin. 8S. N. 951. 18; F. 8.1681; Villers, 3. 271. 
14; Christ. 246. 
Crabro wniglumis. Fab. S. E. 376.12; E,$.2.300. 23; Oliv. Ency. 
Méth. 6. 518. 34. 
Black: head punctured, pubescent, an impressed longitudinal 
line passing from the base of the antenne to the anterior stemma, 
which it surrounds and continues beyond to the centre of the 
vertex, the lower part of the face covered with a silvery down; 
the antennze black, the terminal joints generally fulvous, some- 
times only beneath. 
The thorax pubescent, punctured ; the dorsolum with a central 
and two lateral longitudinal impressed lines, the latter abbre- 
viated ; the scutellum, and post-dorsolum, with a central longi- 
tudinal carina, which extends to the base of the mucro; an incurved 
short hyaline squama on each side of the posterior margin of 
the post-dorsolum; the mucro at the base of the metathorax 
short, generally obtuse, slightly curved and grooved above, the 
sides of the metathorax reticulated; the tubercles generally 
white ; the tegule testaceous ; the wings very slightly coloured, 
