INTRODUCTION. 27 



palpi. My purpose is, to give a review of those characters only, 

 which have been used in the classification, and to furnish some 

 explanations necessary for the better understanding of the present 

 monograph. 



The organs of the mouth of the Tip. brevipalpi afford com- 

 paratively few characters for the classification. The prolongation 

 of the head in front, called the rostrum (compare Monographs, 

 etc., Tol. I, p. xiii) is generally shorter here than in the Tip. 

 longipalpi; it is considerably prolonged in the genera Bham- 

 phidia, Toxorrhina, and Elephantomyia, and then bears the 

 palpi at its tip. The outer envelope of the rostrum has some- 

 times the shape of a short tube ripped open on the under side ; 

 often, however, it is hardly tubular at all, but has rather the 

 appearance of a labrum, and is either short and stout, or long, 

 narrow, and linear (Geranomyia). Whenever I wanted to desig- 

 nate this outer envelope of the rostrum separately, as an inde- 

 pendent organ, I have called it epistoma. The proboscis consists 

 chiefly of the under lip, with its suctorial flabs ; it projects more 

 or less beyond the epistoma ; the flabs are usually somewhat 

 pubescent, linear in the Limnobina, more stout and fleshy in the 

 Limnophilina, Amalopina, etc. ; (in Geranomyia the under lip is 

 very much prolonged and bilobed, the lobes being likewise long 

 and linear). The palpi incurved backwards, when at rest, are 

 four-jointed ; a fifth joint, sometimes perceptible at their basis, 

 probably represents a rudimental maxilla ; Mr. Westwood (Introd. 

 etc. II, p. 525), who makes this suggestion, acids, that the texture 

 of this fifth joint is different from that of the other four. The 

 last joint of the palpi is usually longer than the preceding, some- 

 what linear ; but, except in some rare cases, as in Pedicia, it is 

 never very long. Immediately under the part which I call the 

 epistoma, is a linear, pointed organ, called the tongue; it is espe- 

 cially long in Geranomyia. Meigen (Yol. VI, p. 281), in dissect- 

 ing the mouth of Glochina, also mentions a pair of horny, linear, 

 pointed maxillse. A comparative study of the parts of the mouth 

 of the Tipulidse is yet to be made. 



The eyes are oblong or rounded, separated above by a front 

 which is more or less broad in different genera, but not percep- 

 tibly broader in one sex than in the other. On the under side 

 of the head, the eyes are usually more approximate, often almost 

 contiguous. There is no striking difference in the size of the 



