409 



28. Abdominal dorsal segments 2--8 with the posterior margins armed 



with 10 to 12 short, stout, caudad-projecting teeth; ventral seg- 

 ments 3-8 with a similar series of 6 to 8 



Diamesa waltlii (p. 410) . 



— Abdominal dorsal segments each with a transverse band of stout 



black bristles, each liand consisting of about 5 or 6 rows, located 

 near posterior margins TJialassomyia ohscura. 



29. Abdominal segments each with a conspicuous band of strong spines 



on their posterior margins 30 



— Abdominal segments, with the exception of second, with at most 



weak setulae on posterior margins 31 



30. Apical abdominal appendages each with 3 long and conspicuous 



apical hairs ; thoracic respiratory organ thickest beyond middle . . 

 Metriocnemiis lundhexki (p. 498) . 



— Apical abdominal appendages each with two short and inconspicu- 



ous hairs before apex Ortliocladius flavus. 



31. Abdominal segments, except second, with dorsum nearly uniformly 



covered with short setulae 32 



— Abdominal segments with setulge on dorsum arranged in transverse 



bands of various widths 34 



32. Apex of eighth abdominal segment without long hairs laterally. .33 



— Apex of eighth abdominal segment with two long hairs laterally 



(PL XXXVIII, Fig. 4) . .OrtJwcladius nivoriundus, var. ? (p. — ). 



33. Seventh and eighth abdominal segments each with 4-5 long strap- 



like hairs on lateral margins (PI. XXXVIII, Fig. 5) 



Ortliocladius nivoriundus* (p. 525) . 



— Seventh and eighth abdominal segments each with 1-2 weak 



rounded hairs on lateral margins. . .Ortliocladius sp. D (p. 531). 



34. Thoracic respiratory organs thickest at base, tapering to apex ; third 



abdominal segment with the anterior half almost entirely covered 

 with weak setuls, the apical half with two bands of rather 



stronger setulae, the preapical band broadest 



Cricotopus trifasciatus (p. 504) . 



— Thoracic respiratory organs not thickest, at base ; third abdominal 



segment with a distinct and rather narrow transverse band of 

 setulae near middle 35 



35. The band near middle consisting of two irregular rows of short 



stout spines Ortliocladius sordidellus] . 



— The band near middle consisting of more than two rows of short 



weak setulee 36 



*Johannsen has very briefly described the pupa of Cricotopus varipes. Apart 

 from the colors, which are black aud yellow in varipes and fuscous in nivoriundus, 

 there are no distinctions mentioned. 



tJohannsen subsequently indicated that his identification of this European spe- 

 cies was erroneous. 



