358 



PSYCHE. 



[May, l8gg. 



conditions presented by the labium 

 especially we find an extremely instruc- 

 tive series. 



Sytnplecta puiicfipcnnis. This Tipulid 

 presents mouthparts of the usual Nema- 

 tocerous type, although of a specialized 

 condition of that general type. This 

 specialization is shown in the absence 

 of mandibles and the reduction of the 

 maxillar lobe to a minute, hardly chiti- 

 nized rudiment. The labrum-epipharyiix 

 is rather short, and with chitinized 

 skeletal frame work. The maxillar 



Fig. II, A, Mouthparts of Holorusia riibig 

 inosa, hep. labrum-epipliarjnx, rn.v. max- 

 illa, jnx.l. maxillar lobe, mx.p. maxillar 

 palpus, //. labium, pg. paraglossa; B, La- 

 bium of Tipula sp., pg. paraglossa; S, La- 

 bium of Sjmplecta punctipennis, pg. para- 

 glossa. 



palpi are long, 4-segniented and borne 

 on a short palpifer. The hypopharynx 

 is slender, with pointed fringed apex. 



The labium (fig. 11 S, //) is composed of 

 a narrow well-chitinized basal sclerite 

 with free paraglossae which are rather 

 thick, with concave inner faces and bear 

 numerous short strong hairs, and many 

 short fine prickly hairs. A glossa is not 

 visible. There are no pseudotracheae. 

 Dicranoptycha sp. Here we meet a 

 condition similiar to that shown by 

 Sympkcta. The maxillar lobe is better 

 developed, being a distinct, spoon- 

 shaped, weakly chitinized plate. The 

 labium has free paraglossae, fleshy, 

 with concave inner faces, 

 and without sign of pseudo- 

 tracheae. 



Holorusia rubiginosa. In 

 this giant Tipulid, we find a 

 specialization in the mouth- 

 parts over the conditions 

 presented by Sympkcta and 

 Diccanoptycha shown especi- 

 ally, and most suggestively, 

 in the character of the labi- 

 um. The basal sclerite of 

 the labium (fig. 11 A, //) is 

 very narrow and slender al- 

 though well chitinized an- 

 teriorly, and the paraglossae 

 are no longer free but are 

 fused for two-thirds of their length, 

 forming a single large flat (though 

 rather thick and fleshy) plate, in which 

 a few conspicuous main pseudo-tracheal 

 trunks, and numerous very delicate 

 and inconspicuous small transversal 

 pseudo-tracheae are visible. The })iax- 

 illac (fig. 1 1 A, mx) have only a mi- 

 nute, membranous vestige of a lobe ; the 



