POINTS OP THE ANATOMY OP PO'LTXBNUS LAGTJEUS. 35 



DESCRIPTION OF PLATE III, 



Illustrating Mr. E. G. Heathcote's paper " On Some Points 

 of the Anatomy of Polyxenus lagurus.^" 



Tig 1. — Part of a transverse section through the middle of the body, 

 showing the ventral plate. The bases of the legs are separated and the 

 ventral plate — that is, the fused anterior part of the two " lames pedigferes " 

 of Brandt — occupies the space between them. 



Fig. 2. — Part of a transverse section through the body, showing the female 

 external geiierative appendage. dil. ovid. Dilation of the oviduct. 

 ext. gen. org. External generative organ. 



Pig. 3. — Section through the male generative appendage, dil. vas. def. 

 Dilation of the vas deferens. 



Fig. 4. — Section through the sense organ, ext. cut. External cuticle. 

 hyp. Hypodermis. t. Tube. gan. Ganglion-cell. hyp. c. mass. Hypodermic 

 cell mass. 



Fig. 5. — A transverse section through the fourth segment of a female, to 

 show the ovary, receptacula seminis, and the general arrangement of the 

 organs. The figure is semi-diagrammatic; the oatline of the body, the gut, 

 ovary, receptacula, and nerve-cord being from an actual section ; while the 

 heart, muscles, and fat-body are diagrammatic, g. n. c. The ganglionic part 

 of the nerve-cord. /. n. c. The fibrous part. rec. sem. Receptaculum seminis. 

 spmzoa. Spermatozoa in the receptacula. ovidet. Oviduct. 



Fig. 6. — Part of a transverse section through the posterior part of the body 

 of a female, to show the Malpighian tubes and the ovary, g. n. e. Ganglionic 

 part of nerve-cord. f. n. e. Fibrous part. fol. ov. Follicle round ovum. ov. 

 Ovum. w. ov. Wall of ovary, r. Malp. t. Returning part of the Malpighian 

 tubes. Malp. t. Malpighian tubes. 



Fig. 7. — Part of a section through the testis of a male, showing a follicle 

 containing a sperm morula. /. Follicle, sp. rr.or. Sperm morula. 



Fig. 8. — Part of a longitudinal section through the posterior end, to show 

 the Malpighian tubes, a. d. Anal dilatation, o. w. Outer wall of the gut. 

 malp. t. Malpighian tube. /. malp. t. Lumen of Malpighian tube. memb. 

 Membrane. 



Fig. 9. — Section through gut and Malpighian tubes, malp. t. Malpighian 

 tube. r. malp. t. Reduplicated part of Malpighian tube. memb. Membrane. 



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