357] LARVAE OF THE TENTHREDINOIDEA—YUASA 39 



3(4) Larvapods present on all abdominal segments; antennae with six or seven segments. 



XYELIDAE. 

 4(3) Larvapods not present on all abdominal segments; antennae never with more than five 



segments TENTHREDINIDAE. 



5(2) Thoracic legs seta-like; larvapods wanting; subanal appendages present, setaceous; 



antennae very long, with seven segments PAMPHILIIDAE. 



6(1) Thoracic legs vestigial, not distinctly segmented, mamma-like or wanting, if mamma- 

 like, head and body never distinctly depressed; larvapods wanting 7. 



7(12) Thoracic legs present; ultimate segment with suranal process 8. 



8(9) Subanal appendages present, vestigial, papilliform; ocellarae present; antennae 



with four or five segments CEPHIDAE. 



9(8) Subanal appendages wanting; ocellarae wanting 10. 



10(11) Antennae with three segments; metaspiracles functionless, very much smaller than 



abdominal spiracles 11. 



XIPHYDRIIDAE. 

 11(10) Antennae with one segment; metaspiracles functional, as large as abdominal spir- 

 acles SIRICIDAE. 



12(7) Thoracic legs wanting; ultimate segment without suranal process and subanal 

 appendages ORYSSIDAE. 



MacGillivray (1906) divided the superfamily Tenthredinoidea into 

 nine families. They are the Xyelidae, Pamphiliidae, Blasticotomidae, 

 Tenthredinidae, Xiphydriidae, Siricidae, Megalodontidae, Cephidae, and 

 Oryssidae. The first two families constitute his Generalized Tenthredinoi- 

 dea and the last six his Specialized Tenthredinoidea. Since the Blastico- 

 tomidae and Megalodontidae belong to the Palearctic fauna and are not 

 represented in North America, they are omitted from the foregoing table. 



Family Xyelidae 



Larvae (Fig. 6) of medium size, length 13-18 mm.; body caterpillar 

 like, subcylindrical, flattened on the ventral aspect, uniform in diameter' 

 except last two segments which are suddenly constricted, stout; segmenta- 

 tion and usually annulation distinct; cuticle smooth, tuberculate and 

 setiferous, but never slimy; color greenish, yellowish, whitish, or brownish; 

 tubercles, when present, brownish or blackish and setiferous; prothorax 

 sometimes with a pair of lateral eversible cervical glands in the cervacoria; 

 head circular in frontal contour, moderately large, width usually more 

 than one-half the diameter of the thorax; mouth directed ventrad; head 

 slightly overlapped by the prothorax, if any setae, sparsely and inconspi- 

 cuously setiferous; antennae long, conspicuous, with six, sometimes 

 seven, segments; ocularia about one-fifth the diameter of the antennaria 

 and located caudo-dorsad of it, elevated, ocellarae very small; epicranial 

 suture and vertical furrows present; mouth-parts normal in form; pro- 

 thorax with a large, often colored, shield-like area on the dorsum and 

 lateral aspects; legs in comparison with the size of the body very small, 

 normal in form, all three pairs subequal in size; larvapods present on all 



