4 338. ■ THE IXSECTA. 425 



The predatory Panorpidae, which are rapacious, differ notably from the 

 other Neuroptera, and resemble rather the preceding order. Their oesoph- 

 agus is short and straight, and, in the thorax, is succeeded by a spherical 

 muscular gizzard which is lined internally with a brown chitinous membrane 

 covered with stiff hairs. The stomach is tubular and straight ; the ileum 

 makes two convolutions before passing into the long colon. *^'^' With the 

 other Neuroptera, namely, the Myrmeleonidae, Heraerobidae, Sialidae, and 

 Phryganidae, the oesophagus is long, and dilated, posteriorly, into a kind of 

 pouch ; and often there is a long, thin- walled, sucking stomach inserted on 

 one of its sides. The proper stomach is of a median length, and is more 

 or less transversely constricted.*^'^' The two other portions of the digestive 

 canal are very small and straight. 



The Hymenoptera, which often sip up their fluid flood, have a long oesoph- 

 agus which dilates into a thin-walled, sucking stomach.*-''' With the 

 Vespidae, Apidae, and Andrenidae, this stomach is often only a lateral 

 fold of the oesophagus, and with many Crabonidae, it is attached solely by 

 a short and narrow peduncle.*^'' Many species of this order have a rudi- 

 mentary, callous gizzard, enveloped by the base of the stomach. In the 

 genera Formica, Cynips, Leucospis and Xyphidria, it is very apparent, 

 and consists of a globular, uncurved organ. Those Hymenoptera which are 

 engaged during a long and active life <"' in labors for the raising and sup- 

 port of their young, have a pretty long and flexuous stomach and intestine, 

 and the first has, usually, many constrictions. The Cynipidae, Ichneu- 

 monidae, and Tenthredinidae, which, after copulation and the deposition of 

 their eggs, take no further care in the act of reproduction, have only a very 

 ehort small stomach and intestine. 



But the modifications of each of the various portions of the digestive 

 tubes are most prominent with the sucking Insecta, especially with the 

 Hemiptera.'^' The oesophagus of these last is usually short and small, 

 while the stomach is generally very long, and describes many convolutions 

 in the abdominal cavity. Tliis stomach, as to form and structure, may be 

 divided into two or three distinctly-defined portions. The first consists of 

 a glandular ante-stomach which is straight, large, and divided by several 

 constrictions. The second has the form of a long, flexuous canal, whose 

 walls are glandular, and which dilates, at its posterior extremity, into an 

 oval pouch. *-^' With the Cicadidae, it forms a kind of loop, its posterior 

 extremity being attached to the ante-stomach with Tettigonia, Cercopls, and 



18 Ramdohr, Abhandl. &c. p. 150, Taf. XXVI. 21 With Chrysis, and Hedychrum, this sucking 

 fig. 1, and L. Dufour, Recherch. &c. p. 582, PI. stomach consists of two lateral caeca situated at the 



XI. fig. 169. lower end of the oesophagus ; see Siickow, loc. 



19 Ramdohr, Abhandl. &c. Taf. XVI. fig. 2, Taf. cit. III. Taf. IX. fig. 155, and L. Dufour, loc. cit. 



XVII. fig. 2, Ö; L. Dufour, Recherch. &c. PI. PI. IX. fig. 113, 116. 



XII. XIII. ; and Pictet, Recherch. pour servir d 22 The Apidae, Andrenidae, Vespidae, and Lar- 

 I'hist. et i. I'anat. des Phryganides. ridae. 



The Myrmeleonidae and Hemerobidae, alone, 23 For the digestive apparatus of the Hemiptera, 



have a spherical callous gizzard situated between see Ramdohr, AbhandL &c. Taf. XXII. XXIII. ; 



the stomach and oesophagus. Suckow, loc. cit. III. Taf. VII. VIII.;' L. Du- 



20 See Swammerdamm, Bib. der Nat. Taf. four, Recherch, sur les H6miptöres. p. 20, PI. I.- 



XVIII. fig. 1 ; Treviranux, Verm. Schrift. II. IX.* 



Taf. XIV. XVI. i Brandt and Ratzeburg, Mediz. 24 Ifotonecta, Naucoris, Velia, Lygaeus, Co- 

 Zool. II. Taf. XXV. fig. 29 ; Ramdohr, loc. cit. reus, Pyrrhocoris, Pentatoma, Tetyra, Syro- 

 Taf. XII.-XIV. ; Suckow, loc. cit. III. Taf. VI. mastes, HiC. 

 VII. VIII. ; finally, L. Dufour, Recherch. kc. p. 

 389, PI. V.-X. 



* [ § 338, note 23.] For the digestive appara- Proc. Acad. Nat. Sc. Philad. I. 1847, p. 62. — Ed. 

 tu3 with all its details of Belostoina, see Leidy, 



36* 



