4o6 



WHITMAN. 



EXPLANATION OF PLATE XIV. 

 Letters. 



I-XXXIII = somites. 

 1-66. = number of rings. 



al. = alimentary canal. 

 ale. = gastric csecum. 



b. = brain. 



c. = coelomic cavity leading up to the 



ovaries. 

 ca. = csecal appendage of the ovary. 

 cep. = coelomic epithelium. 

 eg. — caudal appendage. 



d. = ductus ejaculatorius. 

 es. = egg-string. 



f. — fibrous prolongation. 



g. = glandular part of the ejaculatory 



duct. 



gs. = granular secretion. 



i. = inner layer of the spermatophore. 



Im. = longitudinal muscles. 



/u. = lumen of the base of the sper- 

 matophore. 



nc. ~ ventral nerve-cord. 

 n. = nerve. 

 npk. = nephridial pores. 

 0. = outer layer of the spermatophore. 

 ce. = oesophagus. 

 ceg. = oesophageal pair of glands. 

 ov. = ovary. 

 p. = proboscis. 



f/ig^. = first pair of pharyngeal glands. 

 pAg-. — second pair of pharyngeal glands. 

 s. = enlarged end-portion of vas defe- 

 rens commune, 

 sp. = spermatozoa. 

 i. = testes. 

 vd. = vas deferens. 

 vdc. = vas deferens commune. 

 vs. = vesicula seminalis. 

 w. = end of ejaculatory duct. 

 X. = position of the spermatophore. 

 y. = course of the spermatozoa. 



Fig. I. — Transverse section of C/epsine plana, showing coelomic cavities filled 

 with spermatozoa (red), which penetrated the epidermis at the level of the point 

 marked X. The coelomic cavities communicate with the cavity in which the ovaries 

 (ov) lie at the point c. Only about one-half of the section is represented in the 

 figure. X 25. 



Fig. 2. — A part of one of the following sections, showing the base of the sper- 

 matophore and the spermatozoa issuing from it. The arrows show the direction of 

 penetration through the muscular layers. X 120. 



Fig. 3. — Section of coelomic cavities with their peculiar epithelium. X 120. 



Fig. 4a. — Spermatophore, just placed (3.4 mm. long), and full of spermatozoa. 

 The granular substance issuing from the mouth seems to serve the purpose of prepar- 

 ing the way for the penetration of the spermatic elements. X 55- 



(5 = section of the case two days after the escape of the spermatozoa; f = cor- 

 puscles filling the mouth of the spermatophore. X 280. 



Fig. 5. — The central nervous system and sexual organs, together with the pro- 

 boscis, oesophagus, and the so-called salivary glands. X 4h 



Fig. 6. — The supra and sub-cesophageal ganglia, seen from the dorsal side. 



X SO- 



Fig. 7. — The same, seen from the side. X 5°- 



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