Explanation of Plate 1. 



ANTENNAL SENSE-ORGAN OF CULICID^, 



Figs. 1-6. Corethra culiciformis Degeer. 



First and second antennal segments of mature 

 male ; longitudinal section. 



N, main antennal nerve. 



M, antennal muscles within first segment. 



O, anterior head-integument. 



C, chitinous covering of first segment. 



O', posterior portion of layer of ganglion cells. 



N', nervecord which passes through layer of 

 ganglion cells. 



W, transition stages between rods and hypo- 

 dermal cells. 



8t, layer of rods. 



K, basal nuclei of the rods. 



F, fibrous layer. 



O, layer of ganglion cells. 



H, single layer of hypodermls. 



C , chitinous covering of the second segment. 



A, chitinous process of plate. 



P, the plate. 



H', mass of hypodermis behind plate. 



C", chitinous covering of first segment of shaft 

 (third antennal segment). 



N", nervecords of antennal shaft. 



M', muscles of head. 



T, trachea. 



Part of plate with processes drawn in perspective. 



A, chitinous processes. 



P, plate with radial thickenings. 



C", chitinous covering of first segment of shaft. 



3. Section through periphery of plate showing 



bases of processes. 



A. transverse section of a process. 



C , chitinous covering of second antennal seg- 

 ment. 



P, peripheral part of plate. 



4. Sector at about point A of fig. 1 of transverse 



section of second antennal segment of male. 

 A, chitinous process seen in transverse section. 

 C, chitinous covering of second segment. 

 V, radiate spaces between groups of rods. 

 8t, rods. 



K, basal nuclei of rods. 

 F, fibrous layer. 

 O, layer of ganglion cells. 

 H, hypodermis of second segment. 



3. Rods. 



O, ganglion cells of rods. 



F, fiber. 



K, basal nucleus. 



St, body of rod. 

 6. Transverse sections of rods ; a, through base of 

 a rod ; b, through upper nucleus. 



8t, l)ody of rod. 



K, nucleus of rod. 



Fig. 7. Culex. First and second antennal segments of female; longitudinal section. 



N, main antennal nerve. 



M, muscles of first segment. 



C, chitinous covering of first segment. 



N', nervecord which supplies second segment. 



O, outer and inner layers of ganglion cells. 



H, hypodermis. 



C , chitinous covering of second segment. 



8t, rods. 



L, K, V, thicljened parts of chitinous covering of 



second segment. 

 P, plate. 



B, base of shaft. 



C", chitinous covering of first segment of shaft. 

 N", nervecords of shaft. 

 T, trachea. 



29a 



