NEUROPTERA AND COLEOPTERA 309 



On the tenth day the heart is completed on the dorsal side, extending 

 anteriorly where it bends ventrad to end beneath the brain (Fig. 257). 

 The cells of the mycetom at this time appear in a ring around the stomo- 

 daeal valve but are still in the mid-gut. 



The subserosa begins its development early. It appears as a secretion 

 of the serosa cells at the time the tail of the embryo is deeply imbedded in 

 the yolk (Figs. 242, 258). After blastokinesis, as the embryo attains its 

 greatest length, the amnion grows over the interval between the head 

 and the tail in two loops. These meet and fuse so that the embryo 

 everywhere is enclosed in a double-walled sac consisting of the serosa 



Fig. 258. — Brachyrhinus. Section of serosa {ser) at an early stage, {suh. ser) Subserosa 



outside and the amnion inside, with the subserosa lying between (Fig. 

 255). The subserosa becomes hard and leathery and serves as a protec- 

 tive cover for the embryo. After the dorsal wall is completed, the embryo 

 remains enclosed in the subserosa for several days before emerging. 

 When hatching occurs, the leathery cover is split open, and the larva 

 emerges. Thus it is apparent that both the amnion and the serosa 

 together with the subserosa are preserved to the end of the embryonic 

 period. 



References 



Neuroptera: Chrysopa sp.; Bruce (1887), Packard (1871a), Tichomirowa (1890a). 

 C. occelata; Packard (1872), Smith (1922). C. perla; Tichomirowa (1892). Mantispa 

 pagana; Brauer (1855). Osmylus chrysops; David (1936), Hagen (1852). Sialis 

 lutaria; DuBois (1936, 1938), Strindberg (1915). 



Strepsiptera: Aa-oschismus wheeleri; Hughes-Schrader (1924). Halidoxenus sp.; 

 Noskiewicz and Poluszynski (1927). Stylops parvula; Noskiewicz and Polyszynski 

 (1927, 1935). Xenos nigrescens, pallidus, peckii; Brues (1903). X. bohlsi; Hoffmann 

 (1914). 



Coleoptera: Mansour (1927, 19346), Scheinert (1933), Stuhlmann (1886). 

 Acilius sp.; Patten (1887, 1888). Adimonia tenaceti; Henking (18906, 18916, 1892). 

 Adoxus vitis; Joubert (1882). Agelastica alni; FuHnski (1911), Henking (1890-1892), 

 L^caillon (1897), Petrunkewitsch (1898), Smreczynski (1938). Anomala aenea; 

 Rittershaus (1925). Attelabus rhois; Packard (1872). Baris maadipennis; Mansour 

 (1930). Brachyrhinus ligustici; Butt (1936). Bromius vitis; J ouhert (1882). Bruchus 

 quadrimaculatus; Brauer (1925), Brauer and Taylor (1934, 1936). Calandra callosa; 



