Baron Osten Sacken on the Literature of the 
Cs 
(=P) 
bo 
REMARKS ON THE LITERATURE OF THE 
EARLIER STAGES OF THE CYLINDROTO- 
MINA, A SECTION OF THE TIPULIDAL. 
By Baron C. R. Osten Sackxen, Hon. F.E.S. 
In the Monograph of North American Diptera, iv., 
pp. 289-308 (1869), in giving an account of the Section 
Cylindrotomina, I introduced whatever was known about 
their life-history at that time. Very little has been 
added to our knowledge since. What I have done 
now is to overhaul the existing literature for a second 
time, and to prepare a detailed digest of it, arranged 
under the headings of the three principal genera of the 
section. It will be seen that with this mode of treat- 
ment the peculiarities of the larve and pup of the 
Cylindrotomina are brought out with more distinctness 
than they were in my work of 1869 , and that these 
peculiarities fully bear out the intermediate position 
which I have given to that section between the 7ipulidx 
longipalpi and brevipalpi. ‘his intermediate position 
has been further justified by the discovery that, during 
the Oligocene period in Western North America, the 
Cylindrotomina were, apparently, much more common 
than now, and that, for this reason, they may be con- 
sidered as the ancestral form among the present Tipu- 
lide. Many specimens were found in the fossiliferous 
strata about Florissant, Colorado, and the White River, 
Utah. Whether they represent as many species as Mr. 
Scudder makes out of them, remains to be seen. (Com- 
pare Scudder, Tertiary Tipulidee, Proc. Am. Phils isecs 
xxxii., 1894.) 
The three genera of Cylindrotomina, about the trans- 
formations of which I reproduce the (in one case hypo- 
thetical) literature, are :—Phalacrocera, Schin., Oylindro- 
toma, Macq., and Triogma, Schin. The: life- history of 
Ms venus Liogma, introduced by me (Monogr., iv., 
298, 1869), is as yet unknown. 
