LITERATURE OF THE ABDOMEN AND APPENDAGES 183 



noticeable in lepidopterous larvae. They are the valvulce of Bur- 

 meister, and podical plates of Huxley, who also regarded them as 

 the tergites of an eleventh abdominal segment; 1 and the subanal 

 laminae of Heymons. They are wanting in Ephemeridae. 



The infra-anal lobe. Our attention was first called to this lobe or 

 flap, while examining some geometrid larvae. It is a thick, conical, 

 fleshy lobe, often ending in a hard, chitinous point, and situated di- 

 rectly beneath the vent. Its use is evidently to aid in tossing the 

 pellets of excrement away so as to prevent their contact with the 

 body. The end may be sharp and hard or bear a bristle. Whether 

 this lobe is the modified ventral plate of the ninth urite, we will not 

 undertake at present to say. 



The egg-guide. In the Acrydiidse the external opening of the ovi- 

 duct is bounded on the ventral side by a movable, triangular, acute 

 flap, the egg-guide (Fig. 88, B, eg). Whether this occurs in other 

 orders needs to be ascertained. 



LITERATURE ON THE ABDOMEN AND ITS APPENDAGES 

 a. General (including the cerci, stili, etc.) 



Cornelius, C. Beitrage zur naheren Kenntnis von Falingenia longicauda. (Pro- 



gramm d. Real- u. Gewerbeschule zu Elberfeld, 1848, pp. 1-38, 4 Taf.) 

 Schiodte, J. G. Bemerkungen iiber Myrraecophilen. Ueber den Bau des hin- 



terleibes bei einigeii Kafergattungen. (Germar's Zeits. f. Ent., 1844.) 

 De metamorphosi Eleutheratorum observationes. (Naturhist. Tidsskr. 



i-xiii, 1861-1883.) 

 Meinert, F. Anatomia Forficularum. Anatomisk undersogelse af de Danske 



Orentviste, i. (Naturhist. Tidsskr. 3 raekke, ii. 1863, pp. 427-482, 1 PI.) 

 Om dobbelte Saedgange hos insecter. (Naturhist. Tidsskrift, 3 raekke, 



v, 1868.) 

 Tullberg, Tycho. Sveriges Podurider. (Svenska Vetensk.-Akad. Handl., 1872, 



x, Nr. 10, 12 Pis.) 

 Davis, H. Notes on the pygidia and cerci of insects. (Journ. R. Micr. Soc., 



1879, ii.) 

 Westhoff, F. Ueber den Bau des Hypopygiums der Gattung Tipula Meig. 



(Minister, 1882, pp. 1-62, 6 Taf.) 

 Saunders, Edward. Further notes on the terminal segments of aculeate Hyme- 



noptera. (Trans. Entom. Soc. London, 1884, pp. 251-267, 1 PI.) 

 PalmSn, J. A. Ueber paarige Ausfiihrungsgange der Geschlechtsorgane bei 



Insekten. (Helsingfors, 1884, 5 Taf.) 

 Haase, E. Die Abdominalanhange der Insekten mil Berucksichtigung der 



Myriopoden. (Morpholog. Jahrbuch, 1889, xv, pp. 331-435, 2 Taf.) 

 Abdominalanhange bei Hexapoden. (Sitzungsber. d. Gesellsch. natur- 



forsch. Freunde, 1889, pp. 19-29.) 



1 In my account of the anatomy of Melanoplus spretus, 1st Report U. S. Entomo- 

 logical Commission, p. 259, 1 have called these the infra-anal flaps or uro-patagia. 



