PLATE XL 

 Fig. 



1. Transverse section of the cephalic ganglia of Amphiporus lactifloreus, in the line of the 



commissures, the superior of which, from the flattening of the preparation, is shown 

 very plainly, a, proboscis ; d, circular muscular fibres of the body- wall ; k, muscular 

 and cellular stroma of the region, x 90 diam. 



2. Section through the body of the same animal some distance behind the ganglia. The sheath 



for the proboscis now separates the latter from the oesophagus, which has attained 

 considerable size. The lateral nerve-trunks have nearly reached their proper position, 

 viz. to the inner side of the internal muscular layer of the body-wall ; s, granular masses 

 (from the digestive cavity proper) at the sides of the oesophagus. X 55 diam. 



3. Section of the same specimen behind the foregoing and towards the posterior end of the 



oesophageal apparatus, u, ova pressed forward by the contraction of the textures. 



4. Transverse section of the anterior region of the proboscis of Amphiporus pulcher. a, central 



cavity ; 5, the papillary glandular layer ; c, internal circular muscular coat ; d, inner 

 longitudinal layer; e, reticulated or beaded layer ;/, external longitudinal muscular layer; 

 g, external (elastic) layer; h, basement-layer. X 55 diam. 



5. Transverse section of the stylet-region of the proboscis of A. lactifloreus, in the line of the 



marginal sacs. The circumference of the preparation is somewhat distorted from 

 pressure. X 350 diam. 



6. Transverse section of the same region in another specimen, in which the knife has pressed 



aside the basal apparatus of the central stylet (X), and in which the ejaculatory 

 duct (ju) has been cut obliquely. In this and the preceding preparations the peculiar 

 arrangement of the muscular fibres of the region is represented. X 210 diam. 



7. Longitudinal section of the anterior region of the proboscis of Amphiporus lactifloreus. 



X 90 diam. 



8. Longitudinal section of the same region of the proboscis. X 350 diam. 



9. Transverse section of the same part of the proboscis. e, the ends of the longitudinal 



bands of the reticulated layer, which have assumed a finely granular aspect in the pre- 

 paration. X 350 diam. 



10. Glandular papillae in the anterior region of the proboscis of A. lactifloreus, seen in the 



ordinary condition of the organ under pressure. X 210 diam. 



11. Central stylet and basal apparatus of Nemertes Neesii. X 350 diam. 



12. Central stylet of N Neesii. X 700 diam. 



13. Developing or recently repaired central stylet-apparatus of Tetrastemma Candida. X 700 



diam. 



14. Stylet from a marginal sac of the same animal. X 700 diam. 



15. Central stylet and a portion of the basal apparatus in a large Nemertes gracilis. X 350 diam. 



16. Extremity of the posterior region (c) of the proboscis of A. lactifloreus distended with fluid. 



a, a group of the peculiar moving granules. X 90 diam. 



17. Posterior end of a young example of Tetrastemma dorsalis, showing the usual hernia of the 



proboscis under pressure. X 350 diam. 



