202 EEV. A. E. EATON ON KECENT EPHEMEEID^ OE MATELIES. 



10, 12, 13, 13, 11, 8, 5 ; tlie first segment is thoracoid. The squarely truncate pleurae of 

 segments 7 and 8 are minutely mucronate ; those of segment 9 are produced posteriorly 

 each into a short acute triangular point. Porceps-basis of d divided almost completely 

 into two broad divisions ; the limbs 3-jointed, the proximal joint subcylindrical, slightly 

 enlarged or gibbous at the extreme base, and not mvich longer than the remaining joints 

 combined. Ventral lobe of 2 bifid and acutely excised. Penis-lobes narrow, obliquely 

 pointed ; orifices of the seminal ducts placed in proximity to the extreme points of the 

 lobes ; their armatu.re is not obvious in dried specimens, but may resemble in some degree 

 that of the penis-lobes of SijMuriis. Median caudal seta rudimentary, only xV-4 as long 

 as the outer setse ; these are about twice as long as the body in the <s , and 1| as long as it 

 in the ? . OciJi of d contiguous, or nearly so, above, obsoletcly ascalaphoid, with the> 

 upper segments hemispherical and the lower relatively very small. Vertex of ? head 

 transverse ; the occipital border raised in the middle above the level of the posterior orbits 

 of the oculi. Median ocellus smaller than the others ; not isolated, but situated upon the 

 foremost prominence of the upper sm?face of the head. Prouotum of $ broadly reflexed 

 upon the mesopleura?, and in the middle deeply excavated behind. Nymph unknown. 



Type. C. humei'alis (in Palincjema), Walker. 



Distribution. New Zealand and (undescribed sp.) N. America. 



Etymology. Ko\oj3ovpoG, in allusion to the rudimentary median seta. 



CoLOBURTJS HUMERALis, Walker. Plate XVIII. 32 a (wings, legs, and <S genitalia). 



Palingenia humeralis, ! Walk., List of Neuropt. lus. in Brit. Mus. part iii. 552 (1853). 

 X Baetis remota, id., op. cit. part iii. 564 (1853). 



Coloburus [type] humeralis, ! Etii., Eut. Mo. Mag. v. 89 (1868) ; ! id., Traus. Ent. Soc. London (1871), 

 132, pis. iii. 1 & vi. 6-6 b [detail]. 



Subimago [dried). — Wings very light grey, with rather darker narrow mouse-grey 

 borders to the cross veinlets in the greater part of the disk ; but in the fore wing the 

 cross veinlets of the first three areas (excepting those of the pterostigmatic space) and 

 also those in the first ^ of the wing's length between the cubitus (5), prsebrachial (6), 

 and pobrachial (7) nervures are more distinctly edged with sepia-brown; the wing-roots 

 and great cross vein, together with the bases of the principal nervures, are of a duU, 

 very light ochreous tint ; but elsewhere the neuration is dull piceous. Setse light warm 

 sepia- or Vandyke-brown ; the joinings opaque in some examples. 



Imago {dried). — 6 . Notum either pitch-brown or fuscou.s. Abdomen rufo-piceous or 

 opaque burnt-umber. Setie pitch-brown. Pore legs in opaque view pitch-brown; 

 hinder femora and tibiae in opaque view very light raw-umber- or yellowish-brown, 

 changing in transmitted light to pale yellowish amber ; hinder tarsi dull bistre-brown. 

 Wings vitreous, tinged in proximity to the wing-roots with light raw-umber, and in the 

 pterostigmatic region of the fore wing from the costa to the radius with light bistre- 

 brown ; neuration pitch-brown, with the roots of the longitudinal nervures light raw- 

 umber ; cross veinlets of the fore wing edged narrowly with warm sepia-brown between 

 the cubitus (5) and pobrachial (7) nervures in the first ^ of the wing's length, and 

 between the costa and sector (4) in its first | ; those of the pterostigmatic portion of 

 the marginal area branch near the costa and mostly anastomose with one another. 



