371] LARVAE OF THE TENTHREDINOIDEA—YUASA 53 



SPECIES OF THRINAX 



Head pale brown with vertex marked with brown on dorsum and caudad of ocellarae, 

 front with a round brown spot contiguous to ventral apex of the dorsal marking on 

 the vertex, frontal spot not reaching the fronto-clypeal suture; antennae, mouth- 

 parts, femur, tibia, and tarsal claw deep browm; tenth abdominal tergum with a 

 pair of small brown spots; annulation formula, 1, (5, 4, 3), 2, (6, 7); antennae, 5, 4, 

 3, 2, 1 ; labial palpi mth distal two segments subequal; legs with trochanter, femur, and 

 tibia with lengths to each other as 12, 15, and 16 respectively; tarsal claws with the 

 proximal portion shorter than the distal narrow curved portion; length 26 mm.; 

 wadth of head 2 mm.; on fern; M-18 impressatus Provancher. 



Head pale brown with vertex marked with brown on dorsum and caudad of ocellarae, 

 front with a subquadrate spot contiguous to the ventral apex of dorsal marking of the 

 vertex, frontal spot reaching the fronto-cl3Tjeal suture; antennae, labrum, mouth- 

 parts, femur, tibia, and tarsal claw deep brown; tenth abdominal tergum with a 

 pair of large brown spots; anmJation, 1(5, 4, 3, 1), (6, 7); antennae, 5, 4, 1, 3, 2; 

 labial palpi with distal segment longer than the preceding; legs with trochanter, 

 femur, and tibia with lengths to each other as 12, 15 and 16 respectively; tarsal claws 

 with the proximal portion as long as the distal curved portion; length 25 mm.; 

 width of head, 2 mm.; on fern; Y-20-3-1, -20-1 pulatus MacGillivray. 



Strongylogaster Dahlbom 



Larvae small comparatively speaking, length less than 24 mm.; body 



slender, finely annulate, uniformly green; head pale or light brown or 



sometimes with a few spots; tenth abdominal tergum never distinctly 



marked; larvapods usually with less than ten setae; thoracic legs normal in 



form, femur and tibia subequal to each other or one longer than the other; 



labrum pale brown or whitish, with three to six setae on each side; glandu- 



bae usually subequal in length to adjacent setae; spiracles often faintly 



winged. 



SPECIES OF STRONGYLOGASTER 



1(2) Head with blackish brown markings, vertex with a pair of diverging spots over the 

 vertical furrows directed toward ocellarae and a spot caudad of each ocellara; 

 vertical markings sometimes faint, sometimes very distinct and large, merging into a 

 continuous vertical marking; front never with spot; antennae, labrum, and mouth- 

 parts light brown; tenth abdominal tergum usually without markings, rarely with a 

 pair of faint spots; annulation, 1, 4, (2,3, 5), (6, 7,) ; antennae, 1, 5, (2, 3, 4); maxillary 

 palpi, 2, (1, 4), 3; labial palpi with two distal segments equal in length to each other, 

 shorter than distal segment of maxillary palpi; labrum with three or four setae on 

 each side; mandible with two, rarely three, setae; legs with trochanter, femur, and 

 tibia with lengths to each other as 10, 10, and 12 respectively; uropods with about 

 eight or nine setae, five on cephalic, 3-4 on lateral, and one on caudal aspect; glandu- 

 bae long, slender, subequal in length to adjacent setae; spiracles not winged; length 

 18 mm.; width of head 1.8 mm.; on Pteris aquilina; Y-21 annulostis Norton. 



2(1) Head without blackish brown markings, uniformly pale brown 3. 



3(4) Trochanter distinctly shorter than femur; labial palpi with distal segment as long 

 as the preceding segment; head uniformly pale; body and legs uniformly green 

 without markings; annulation, 1, (3, 4, 5), (6, 7, 2); antennae slender, 5, 1, (4, 3, 2); 

 maxillary palpi, (2, 1), (4, 3), distal segment longer than that of labial palpi; labrum 



