GENERA OF EXOTIC MICROPTERYGIDES. 161 



J 1 .nd 3 remote, transverse vein between 3 and 4 well-defined, the four main veins 

 lot connected at base of wing, 11 from middle of cell, 11 and 12 without additional 

 jranches" [Trans. New Zealand Inst., xviii., pp. 180-181 (1886)]. 



Comparing this genus with the typical genus Micropteryx, Meyrick 

 says it " differs by the stalking of veins 7 and 8 in both wings, and the 

 additional branch of 11 in fore-wings." He further adds [2V. New 

 Zeal. Inst., xx. (1888), p. 91] that " in P. doroxena veins 7 and 8 of both 



wings are separate and the generic definition should be 



widened to include this case. The genus remains distinct from 

 Micropteryx by the presence of the additional branch of vein 11 of the 

 fore-wings." 



MNESARCHAEA. Imago : Head loosely haired, somewhat rough ; tongue obsolete, 

 ocelli present. Antennae if, stout, filiform, in male simple, basal joint moderate, with- 

 out pecten. Labial palpi moderately long, straight, porrected, clothed with long loose 

 scales, forming a dilated terminal brush. Abdomen, in male, with uncus and valves 

 well developed, and two long linear internal processes. Posterior tibise thinly clothed 

 with long bristles, middle and posterior tarsi with whorls of projecting bristles at 

 apex of four basal joints. Fore-wings with vein 1 simple, 2 almost from angle of 

 cell, 6 out of stalk of 7 and 8 near base, 7 and 8 stalked, 7 to hind margin, 11 

 absent. Hind- wings of fore-wings, lanceolate, cilia rather over 1; neuration 

 'exactly as in fore-wings, except that vein 6 is separate from 7 [Trans. New. Zeal. 

 Inst.. xviii., p. 180 (1886;]. 



To this diagnosis Meyrick adds (Ibid., xx. (1888), p. 90) : " In M. 

 lo.i-oacia and M. hemadelpha, the tongue is well- developed, and vein 

 6 of the fore-wings is separate ; in all other respects the structure is 

 identical with that of M. paracosma. The antennae in all the species 

 are clothed with loose hair-scales, arranged in whorls at the joints ; 

 the spurs of the middle tibiae are well developed." 



The comparison of the neuration of Palaeomicra with that of 

 certain Trichopterygids led to a most interesting statement by Meyrick, 

 who writes : " The nearest of these (Trichopterygids) to Palaeomicra is 

 Il/n/acopfiila (Rhyacophittdtu) ; Cyrnus and Holocentropus (Hydropsy - 

 chidae) also approximate closely, and Diplectrona and Hydropsyche in 

 the same family, less nearly ; Calamoceras (Leptoceridae) is rather 

 more remote. In the fore-wings of Rhyacophila the only important 

 difference is the existence of an additional vein rising out of 4 ; but in 

 the hind-wings one observes, with interest, that this very difference has 

 disappeared, this additional vein being absent ; throughout these 

 genera it seems that, in the tendency to a progressive simplification of 

 structure, the hind-wings took the lead, with the result that in the 

 finally established lepidopterous type the hind-wings have permanently 

 four veins less than the fore-wings. lihyacophila shows no other 

 essential difference from Palaeomicra ; the other points of difference 

 consist in the position (whether above or below the furcations) 

 of the transverse bars, or their partial obsolescence. Palaeomicra 

 chalcnphanes is especially interesting, as being at present the only 

 Lepidopteron known which shows the basal trifurcation of vein 1 a of 

 the fore-wings, common to all the above-mentioned genera of Trich- 

 optera ; and the same species possesses the second (basal) branch of 

 vein 12 of the fore-wings, which is shown in Rhyacophila, but not in 

 any of the others mentioned, except Hydroptyche, which does not, 

 however, show the other or median branch. I may add that this 

 basal branch is, perhaps, rather to be regarded as a transverse bar 

 connecting vein 12 with the costa, than as a true branch. It appears 

 to me that the type of neuration of the Trichoptera consists of five 



K 



