BY THOMAS G. SLOAN'E. 195 



Tachyta Kirby, 1837 (V. bnoinipctuiis j\Iacl.) ; Elaphropus Motscliiilsky, 

 1839 (2'. bifoveatuti MacL); Tachylopha Motschulsky, 1862 (T. spericeri SI.); 

 Tachyura Motschulsky, 1862 {T. curticollh SI.)*; Folyderis Motschulsky, 1862 

 (T. captus Blackb. ) 



I gi\'e below some notes on characters which vary in the genus Tachys. 



Antennae. — There is considerable difference in the length of the antennae 

 owing to differences in tlie form of the joints; T. macleayi SI., shows the 

 loift^est antennae with the longest joints, and T. captiif! Blackb., one of the 

 shortest with miiniliform joints. The relative length of the second and third 

 joints varies, in 1'. murrumbidgeneis SI., the second joint is shorter than the 

 third, in T. macleayi longer; the longer second joint seems a recent character. 



Frontal sulci. — The front is always bi-impressed ; two chief forms of the 

 sulci may be noted, viz., (1) short, not extending on to the clypeus, and (2) 

 elongate, extending across the clypeus; the elongate sulci, in traversing tbe 

 clypeus, isolate the fixed seta on each side. The short form of the sulci is the 

 ordinary one, and evidently the most ancient, l)ut the single character of a 

 similarity in the form of the frontal sulci does not in itself show near relation- 

 ship between species. 



Prothoraoc. — The prothorax shows many variations in shape; it may' be 

 convex, or depressed, it may have the base wide with sharply rectangiilar angles, 

 the sides parallel })osteriorly (T. ectromioides SI. ), or the base narrow, the 

 sides strongly rounded and sinuate before the base (2'. monochmts Schm.) ; and 

 there are many other variations in shape. The base is always more or less 

 pi'oduced backward in the middle, the degree of prominence varying consider- 

 ably. The posterior angles vary a good deal. A transverse sulcus across the 

 base, defining a median basal area, is almost always present, but is wanting in T. 

 spenceri SI., and T. iaapidiCHS SI. ; it is generally more or less punctate, simple 

 in T. lindi Blackb., and .5-foveate in T. cnnvexus MacL, and in the Oriental 

 species T. interpunctatus Putz. Some species have a short longitudinal submar- 

 ginal carina near each basal angle, but this character does not seem in itself of 

 much use in showing relationships between species. 



Elytra. — The striation may vary from fully striate {i.e., 9-striate) as in 

 T. amplipennis Macl. to laevigate (without striae) as in T. macleayi; in species 

 with less than nine striae any number from eight (seventh obsolete), as in T. 

 tnonochrous, to one, as in T. bifoveatus Macl., may occur; the outer stria is suc- 

 cessively lost as the number becomes less, with the result that the first is the 

 most persistent. The varying forms of the eighth stria and ninth interstice are 

 of high taxonomie value; the eighth stria may be deep, simple, and entire, 

 with the ninth interstice convex, or entire with the ninth interstice depressed, 

 or it may consist of a row of punctures along the side, or it may be obsolete 

 on the side though well marked towards the apex, or it may be altogether 

 obsolete. A striole (apical striole) is present in nearly all species of Tachys on 

 the apical declivity of each elytron ; it is sometimes near the margin, in about 

 the position of the normal seventh stria, though usually it is about the middle 

 line of the elytra. The apical striole is evidently derived from the apical 

 part of the seventh stria, and the interval between it and the eighth stria is 



*Bates, after 1881, habitually used the subgeneric term Barytachys (which he 

 attributed to Chaudoirl for Tachys klugi Nietner, and many allied species ( T . 

 bipustv.lus Macl., is an allied Australian species) but I have not been able to 

 trace the name Barytachys in the literature available to me, nor to find out in 

 what way it differs from Tachyura. 



