TIPULID^. 271 



thorax. The prothorax is generally reduced to a more or less 

 disc-shaped piece, conspicuously separated from the mesothorax 

 by a narrow groove. This piece was called the collare by Osten 

 Sackeu, and though a better name could not be found for it, at all 

 events in this family, but few authors have adopted it, and in the 

 present volume it is sometimes spoken of by that name, sometimes 

 (when least distinct) as the prothorax. 



The mesothorax bears the characteristic V-shaped suture 

 running transversely across its middle. This is always present, 

 but iu some cases, specific or individual, it is rather less obvious, 

 whilst its indistinctness in the PTYCIIOPTERIN^ is one of the 

 characters of that subfamily. 



A peculiar feature present in a large number of species is a 

 small indentation, often amounting to a small hole (generally 

 with a small shining black or brown spot at the bottom), placed 

 behind each shoulder, in which region the surface itself is nearly 

 always somewhat sunken. No use has as yet been assigned to 

 them, but Osten Sacken suggested that they might have some 

 connection with the prothoracic spiracles that are placed near 

 and immediately below them. They appear to reach their 

 greatest development in LimnopJdla. Another minor pecu- 

 liarity is the presence of "two closely approximated shining 

 dots, black or brown, near the point of contact of the inter- 

 mediate thoracic stripe with the collare." This has been noticed 

 by the present author also in many species. 



The whole thorax usually has a bare appearance, as pubescence, 

 except such of microscopic proportions, is mainly confined to a 

 little hair around the base of the wings. There is nothing in the 

 TiPULiDyE of the nature of macrochcetce (or distinct stiff bristles, 

 arranged in some regular manner) ; but in some genera there is a 

 row on each side of the middle (the rows generally well separated) 

 of rather longer and stiffer hairs than those forming the general 

 pubescence. This is most noticeable in Erioptera, of the Oriental 

 genera, the rows (which are composed sometimes of single hairs, 

 sometimes of two or more abreast, irregularly placed) diverging at 

 the suture towards the hind corners of the dorsum. 



The scutellum is always more or less semicircular and com- 

 paratively small, and the metanotum in the great majority of genera 

 is conspicuously developed. 



ABDOMEX always elongate, considerably longer than the thorax, 

 generally cylindrical, or with the dorsum somewhat flattened ; the 

 sides as a rule straight and parallel, except that in the female the 

 abdomen is in many species slightly widened just beyond the 

 middle ; the tip in the male usually squarish in shape, clubbed, or 

 only slightly thickened, in the female drawn out conically. There 

 are invariably eight segments, though these are not always 

 obvious ; the first generally short, closely and broadly attached to 

 the thorax, the second, especially in Tipula, usually the longest, 

 the remainder more or less subequal ; the whole abdomen shortly 

 and inconspicuously pubescent. 



