1910.] FOSSORIAL WASPS OF AUSTRALIA. 345 



I cannot agree with Kohl in treating these forms as different. 

 The extreme specimens of a series show considerable difference 

 in the sculpture on the mesopleurse, but intermediate forms, of 

 which the type of globosus is one, seem to occur. The pile on the 

 sides of the abdominal segments seems to be present in all fresh 

 specimens, and the brown margin of the abdominal segments 

 is variable, almost absent in the type. I have not seen any 

 specimens exceeding 17 mm. in length. 



Sphex (Isodontia) abditus Kohl, st. nugenti, st. n. 



5 . Differs from the typical form in the following details : — 

 the second joint of the flagellum is distinctly longer than the 

 third, the punctures on the thorax are very shallow, the pubes- 

 cence on the thorax and median segment is black, erect, and 

 sparse, and the apical joint of the tarsi is ferruginous, leaving 

 only the coxae and trochanters black on the legs. 



Length 19 mm. 



Hab. Cairns, Q. 



Kohl gives the locality Sikkim, but expresses doubt as to the 

 correctness of the information. In my opinion abditus is scarcely 

 distinct from aurifrons Sm. from Aru, the latter species differing 

 in the testaceous margins of the abdominal segments which are 

 also slightly pruinose. In Queensland the present form seems to 

 be very scarce and has not been previously recorded. 



Sphex vestitus Sm. 



Sphex vestita Sm. Oat. Hym. B. M. iv. p. 248 (1856), 2 . 



Sphex prcetexta Sm. Brenchley's Cruise of the ' Curacoa,' 

 p. 461 (1873), 2 ■ 



Sphex imperialis Kohl, Ann. Naturh. Hofmus. Wien, v. p. 398 

 (1890), $. 



This is very near cognatus Sm., but where they occur together 

 the female cognatus has the wings flavo-hyaline at the base, and 

 the pubescence on the median segment is much paler in both 

 sexes. The male genitalia are also different, the eighth ventral 

 segment being produced into a point in cognatus, whilst in vestitus 

 it is deeply longitudinally grooved beneath and not pointed ; the 

 petiole is somewhat longer in cognatus, and it is a much smaller 

 species than vestitus. Kohl gives prcetexta as a synonym of 

 formosus, but this is not correct. 



Hah. Gayndah, Q. [Kohl) ; Mackay and Cairns, Q. (Turner). 



Sphex cognatus Sm. 



Sphex cognata Sm. Cat. Hym. B. M. iv. p. 248 (1856), § . 

 iSphex opulenta Sm. Cat. Hym. B. M. iv. p. 250 (1856), rf. 

 Sphex formosa Sm. Cat. Hym. B. M. iv. p. 254 (1856), $ . 

 Kohl gives opidenta as a synonym of umbrosus, but it is quite 

 distinct from that species. 



Hab. Australia (the northern half) ; Ceram ; Semao Isl. 



