CoE.— Nemerteans. 



PLATE 20. 



Fig. 121. Amphlporua occidentalis Coe. 

 Figs. 122 to 127. Amphlporus gelatinosus Coe. 

 Fig. 128. Drepanophorus ritteri Coe. 



Fig. 121. Amphlporus occidentalis. Reconstruction of anterior portion of 

 alimentary canal, showing rhynchodaeal opening {ro), esophagus 

 (e), esophageal caecum (ec) with appendix {ap2)) thereto, cardiac 

 caecum {cue), stomach (st), pylorus (pyl), opening into intestine 

 (i), at point marked x, and intestinal caecum (ic), with its paired 

 anterior branches (ic'). The asteri.sk (*) denotes position of 

 most anterior sexual glands. 



Fig. 122. Amphiporus gelatinosus. Portion of transverse section of body in 

 intestinal region, showing the great amount of parenchyma 

 which surrounds the intestine {in) and its lateral diverticula {id). 

 The very small proboscis sheath with the dorsal vessel beneath it 

 is widely separated from the dorsal body walls by the thick mass 

 of parenchyma. The .sexual glands (ov), each containing a single 

 ovum, lie free in the parenchyma beneath the body walls, which 

 are remarkably thin as compared with the size of the body. 

 X 20. 



Fig. 123. A. gelatinosus. Portion of musculature of body wall in brain region, 

 showing the great numbers of submuscular glands (smg) lying 

 between the bundles of longitudinal muscles (Im) and opening 

 directly to the exterior of the body. X 120. 



Fig. 124. A. gelatinosus. Various forms of connective tissue elements which 

 constitute the cellular stmcture of the body parenchyma. X 1000. 



Figs. 12-5-127. A. gelatinosus. Three stages in the development of the single 

 ovum which matures in each gonad; ji, nucleus (germinal vesicle) 

 of ovum ; 2/n, yolk nucleus ; fo, follicle which surrounds ovum 

 and later forms the efferent duct (fo') ; a, attachment of ovum to 

 follicle. Figs. 125, 126, X 250 ; Fig. 127, X 160. 



Fig. 128. Drepanophorus ritteri. Portion of integument and underlying 

 basement membrane and circular musculature, showing the 

 peculiar deep staining basal glands {bg) which occupy the deep- 

 est layer of the integument. X 300. 



