BY ROWLAND E. TURNER. 221 



172. T. shuckardi Guer. 



Thynnus shuckardi Guer., Mag. de Zool. xii. p.7, P. 100, fig.13, 

 1842 (£)-, Westw., Arc. Ent. ii. 2, p.136, <J$, P.83, fig.5, $, 1844 



The male of this species is very well figured by Guerin. It is 

 a very common species in the neighbourhood of Sydney, and may 

 be distinguished from the allied Victorian T. guerinii Westw., by 

 the pubescence on the median segment, which is golden in 

 T. shuckardi and white in T. guerinii. The breadth of the 

 hypopygium is variable in both species, and I should certainly be 

 inclined to sink Westwood's name were it not that the females 

 received from Mr. French as those of T. guerinii show a marked 

 difference in the sculpture of the second abdominal segments, 

 showing about thirteen transverse carinse instead of about eight, 

 as in T. shuckardi. The fifth abdominal segment beneath is 

 transversely rugose in T. shuckardi, strongly obliquely rugose- 

 striate in T. guerinii. The pygidium seems to be rather narrower 

 in T. shuckardi. T. flaviventris Guer., is also very near, but 

 always has the two apical abdominal segments black; and the 

 female will probably prove to be distinct. 



Hob. — Sydney. 



173. T. guerinii Westw. 



Thynnus guerinii Westw., Arc. Ent. ii. 2, p.137, 1844(<J). 



The male, as I have stated, seems only to differ from T. shuck- 

 ardi in the colour of the pile on the median segment. 



Q. Head shining, front strongly, vertex delicately and sparsely 

 punctured; much broader than long, convex, rounded at posterior 

 angles. Pronotum nearly smooth, half as broad again as long, 

 sides parallel, anterior margin straight, with a row of deep 

 punctures from each of which springs a long hair. Mesonotum 

 and median segment punctured, median segment widened from 

 base to the truncation, vertically truncate posteriorly. First 

 joint of anterior tarsi very broad and strongly emarginate at base 

 on inner margin. First abdominal segment vertically truncate 



