124 A DECADE OF AUSTRALIAN THYNNIDEOUS INSECTS. 
I have hitherto observed in no other insect, having the coxze 
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 elongato, segmentis constrictis, ultimis duobus 
ferrugineis, ano dentato dentibus duobus primis minoribus segmentoque penultimo etiain 
tridentato, pedibus nigris. 
Long. corp. lin. 5. Expans. alar. lin. 94. 
Habitat in Terra Van Diemenii, Mus. Westw. Communic. Dom. J. Hooker. 
Obs. 3.—I have detected (June 14, 1844,) a third Australian 
species of Aeclurus in the collection of my friend G. H. K. Thwaites, 
Esq., of Bristol, of which the following are the characters :— 
Aelurus merens; niger, capite et thorace obscuris cinereo paullo setosis, abdomine elongato- 
ovato, segmento ultimo lateribus rotundatis apice in spinam parvam producto ; capite setis 
longis griseis postice marginato, maxillis et labio ut in congeneribus, alis fusco-tinetis. 
Long. corp. lin. 7. Expans. alarum lin. 135. 
Habitat apud Melbourne (Noy. Holl.) Mus. Thwaites. 
