494 ^- ^- MOORE. 



EXPLANATION OF PLATE XXVL 



Fig. I. Ventral view of anterior region. X 3. ^, male pore. 9> female pore. 

 CL, clitellum. i a, posterior five somites. 



Fig. 2. Side view of anterior region. X 3. Letters as in Fig. i. 



Fig. 3. Dorsal view of same. Letters as before. Z>., dorsal pores. 



Fig. 4. Worm opened in dorsal median line. X 8. B., buccal chamber. S.G., 

 supra-oesophageal ganglia. GL, glandular masses attached to oesophagus and 

 pharynx. C.v., contractile lateral trunks. C.oe., ciliated region of oesophagus 

 (calciferous ? gland). Cr., crop. C, gizzard. /., intestine. CL, clitellum. D., 

 dorsal trunk. P., prostate. S.d., sperm duct. F., ciliated rosettes. T., testes. 

 The sperm sacs have been removed to show the structures beneath. 



Fig. 5. Longitudinal median section. X15. B.m., radiating buccal muscles 

 (retractors). S.c, supra-oesophageal commissure. Ph., pharyngeal sac. GL, 

 glandular masses. S., sperm sacs ; the two pairs overlap, and consequently both 

 are cut in each somite. V.c, ventral nerve cord. Oe., papilliforln portion of 

 oesophagus. Cc?^., ciliated region of oesophagus (calciferous gland?). V., valvu- 

 lar folds terminating this portion of oesophagus. Cr., crop. Va., valvular fold 

 depending from dorsal and lateral walls. (The intestine in section shown was 

 somewhat twisted, and was cut in the lateral portion of the fold below. There is 

 no fold in the ventral region.) G., gizzard. 



Fig. 6. Longitudinal section through setigerous gland and post-setal gland of 

 somite XIII. X 250. Coe., coelomic membrane. G., gland cells. S.m., muscles 

 of seta. L.m., longitudinal muscle layer. Cm., circular muscle layer. (?.«., 

 necks of gland cells. C, cuticle. S., seta. S.g., Invagination of hypodermis to 

 form setigerous glands. M., mass of secreted material in cavity of post-setal 

 gland. 



Fig. 7. Longitudinal section of anterior region of oesophagus. X400. L.m., 

 longitudinal muscle layer. C.vi., circular ditto. E., papillae of columnar epi- 

 thelium. 



Fig. 8. 8 a, transverse section just in front of ciliated region of oesophagus. 

 8 b, three sections back of a. Ciliation commencing and lacunae, Ca., appearing 

 in walls. 8 c, a transverse section about six sections posterior to 8 <5. 8 </, a trans- 

 verse section in the hinder region of ciUated tract. P.vi., musculo-peritoneal layer. 

 E., ciliated epithelial layer. Ca., lacunae between vascular lamellae. 8^, section 

 through region of valvular folds ( V. in Fig. 5) terminating the ciliated tract. All 

 X50. 



Fig. 9. Cross section of portion of ciliated tract (calciferous glands ?) to show 

 histology. X400. C.w., circular muscle layer. L.m., longitudinal ditto. B.v., 

 radiating longitudinal blood vessels. N., nuclei lying in protoplasmic mass on 

 walls of blood canals. C, masses of these nuclei contiguous with epithelial and 

 with muscular layers. E., ciliated lining epithelium of oesophageal tract. 



Fig. 10. Tangential section through one of the circular trunks of ciliated 

 region of oesophagus. X 400. C.v., circular trunk. B.v., longitudinal vessels 

 given off from C.v. N., nucleated protoplasmic mass on walls of blood vessels. 

 A section through this region in a plane parallel to that of Fig. 9 would show the 

 radiating vessels connected by a great annular trunk at their outer ends. 



