BY TII0MA8 G. SLOANE. 197 



which it is (in the sixth interstice a similar irregularity occurs, though in these 

 species the third stria and interstice are regular. 



Tarsi. — In 'I'achys the posterior tarsi are generally elongate and slender, 

 but are short and stout in T. murrumbidgensis. The length of the first joint 

 varies from longer than the three succeeding joints together, to shorter than the 

 two succeeding joints together. Some use has been made of the differences in 

 length of the posterior tarsi, but I have not given sufficient attention to the 

 question of the variations of the posterior tarsi in the genus Tachys to enable 

 me to speak confidently regarding the taxonomic value of such differences as I 

 have observed ; attention may be drawn to the relatively short posterior tarsi of 

 T. onensensis Blackb., in comparison with the elongate ones of T. striolatus 

 Macl. 



Colour. — The colours in the tribe Bembidiini are very variable; as a rule 

 sombre colours must be looked upon as more primitive than bright colours, or 

 lively patterns. Joints 7 — 11 of the antennae are T>allid in Tachys macleayi and 

 T. ovatus, species not at all nearly related to one another. A similar paleness of 

 some of the joints of the antennae occurs in many species of the tribe Odacan- 

 thini, especially those of South America, also in the Australian genus Homothes 

 of the tribe Anchomenini (//. elegans Newm., joints 7 and 8, H. velutirms Macl., 

 joints 7 — 10 pallid). Somewhat similar spots on the elytra to those which 

 occur in many species of Tachys are found in the tribe Odacanthini. I would 

 note here that these pallid joints of the antennae and pale spots of the elytra 

 in the tribe Odacanthini are more ancient than the present-dav genera, and 

 probably have considerable taxonomic value; they seem to be "recognition" — 

 or "warning" — marks. 



Table of Australian Species. 



1 (281 Elytra with ninth interstice convex; eighth stria strongly impressed: 



two setiferous punctures on disc, on or at position of third interstice. 



2 (51 Elytra without apical striole. (Prothorax with a '.submarginal carina. 



Colour brownish testaceous.) 



3 (4 1 Elytra 9-striate: interstices ordinary, convex. 3.3 mm., 



ampHpemns Macl. 



4 (31 Elytra 17-striate ; eight inner striae duphcated. 3.3 mm., nervosus SI. 



5 (2 1 Elytra with distinct apical striole, a distinct puncture beside inner 



margin of apical striole far back. 



6 (25) Prothorax with a transverse basal impression. Elytra with border not 



prominent behind humeral angles; lateral channel passing round 

 humeral angles. 



7 (241 Frontal sulci short, wide apart, not extending on to clypeus. 



8 (23) Prothorax with posterior angles not forming a prominent tubercle. 



9 (16) Prothorax with base wide, truncate on each side; lateral basal im- 



pressions distant and separated from lateral margin by a wide de- 

 pressed space. 



10 (131 Elytra with fifth stria uniting with marginal channel at base; 4-macu- 



late. 



11 (12) Elytra with all striae indicated, seventh short, only impressed in 



middle: humeral macula extending from fifth stria to margin. 2.8 

 mm banksi SI. 



12 (11) Elytra 6-striate (seventh stria obsolete): humeral macula on interstices 



7 and 8, not reaching base. 3.1 mm bnprestioidcs SI. 



13 (10 1 Elytra with fifth stria not reaching base; 2-maculate. 



14 (15) Elytra 6-striate. 2.2 — 2.6 mm bipustulnfvs Macl. 



15 (14) Elytra .5-Btriate. 2,9 mm solidHS SI. 



16 (9) Prothorax angustate posteriorly: base not or hardly wider than apex; 



lateral basal impressions deep, concave, narrowly divided from 

 lateral margin by a convex interspace. 



