124 
A DECADE OF AUSTRALIAN THYNNIDEOUS INSECTS. 
I have hitherto observed in no other insect, having the coxre 
dilated, and together forming a broad nearly circular cup, with the 
margins elevated, large enough to allow the under-side of the head 
to rest within it when deflexed- 
Obs* 2.—Thynnus decipiens (ante, p. 105), is closely allied to 
T. dimidiatus above described; it may be thus characterized :— 
T. decipiens ; niger punctatissimus, abdomine elongate, segmentis constrictis, ultimis duobus 
ferrugineis, ano dentaio dentibus duobus primis minoribus segmentoque penultimo etiam 
tridentato, pedibus nigds. 
Long. corp. lin. 5. Expaiis. alar. lin. 
Habitat in Terra Van Diemenii, Mas. Westw. Communic. Dorn. J, Hooker. 
Ohs. 3.—I have detected (June 14, 1844,) a third Australian 
species of Aelurus in the collection of my friend G. H. K. Thwaites, 
Esq., of Bristol, of which the following are the characters:— 
Aelurus mcerens; niger, capite et thoracc obscuris cinereo paullo setosis, abdomine elongato- 
ovato, segmento uhimo latcribus rotundatis apice in spinam parvam producto^ capite setis 
longis griseis postice marginato, maxillis et labio ut in congeneiibus, alis fusco-tinctis. 
Long. corp. lin. 7. Expans, alarum lin. 13^, 
Habitat apud Melbourne (Nov. Holl.) Mus. Thwaites. 
