Mesenchytraeus

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Mesenchytraeus solifugus by Moore.png
Morphology of Mesenchytraeus solifugus (Oligochaeta: Enchytraeidae).

1. A ventral view of the anterior twelve somites of the worm, showing the position of the spermathecal and male and female genital pores. ×20.
   • st – spermathecal pore at IV–V;
   • ♂ – male pore;
   • ♀ – female pore.
2. Profile view of the anterior thirteen somites of the same specimien, showing the position of the setae bundles. The lips of the atrium are everted to form a penis. ×20.
   • Lettering as before.
3. Semidiagrammatic figure of the reproductive organs contained in somites XI–XXII. ×35.
   • t – testes;
   • ss – left sperm sac;
   • rss – right rudimentary sperm sac;
   • sf – sperm funnel;
   • vd – sperm ducts (the right one, lying within the ovisac, is here represented diagrammatically as nearly straight; the left, lying in the coelom, is exhibited with nearly its actual arrangement of folds and coils);
   • se – saccus ejaculatorius;
   • a – atrium;
   • ♂ – male pore, here shown in a position much more lateral than is proper;
   • ov – ovaries;
   • ovs – the single ovisac, here represented as only partly filled with ova;
   • ♀ – female pore in a position more lateral than is natural.
4. Ouitline of the supraoesophageal gland, from a dissection. ×48.
5. Outline and optical section of a spermatheca showing the three diverticula and the external pore below; the upper end is broken and the ampulla not so large as usual. The poinit where the break is indicated is about where it becomes continuous with its fellow and opens into the oesophagus. ×48.
6. A section through somite XVI, showing the relation of the sperm sac, ovisac and the sperm ducts to one another and the intestine and nerve cord. ×55.
   • ss – sperm sac filled with developing spermatozoa;
   • ovs – ovisac containing ova and the right sperm duct;
   • lvd – left sperm sac;
   • nc – nerve cord.
7. Median vertical section through the anterior end. ×55.
   • m – mouth;
   • cp – cephalic pore;
   • eg – supraoesophageal ganglion;
   • ne – ventral nerve cord;
   • ph – pharyngeal pad.
8. Section of a small portion of the body wall, from the preclitellar region, showing the remarkable development of pigment granules in the epidermis. ×440.

Mesenchytraeus solifugus by Emery.png
Morphology of Mesenchytraeus solifugus (Oligochaeta: Enchytraeidae).

Explanations: cd – dorsal chaetae; cv – ventral chaetae; ce – brain; cu – cuticle; h – hypoderm; i – intestine; in – funnel; lc – cephalic lobe; ml – longitudinal muscles; mt – transversal muscles; ne – nephridium; nv – ventral ganglion chain; o – mouth; ph – pharynx; pn – nephridial pore; se – septum.

1. Habitus. x9
2. Brain and oesophageal ring; reconstucted from a series of horizontal sections. In front of the brain the cephalic lobe shows a thickened hypoderm, with pigmented sense cells. x130
3. Sagittal section of the foremost part of the body (combined from a series of not perfectly sagittal sections), pc – cephalic pore, v – blood vessel. x130
4. System of muscular bundles, which move the pharynx (m, ph); reconstruction; the outer wall of the body is supposed to be transparent. Of internal organs, the central nerve system and the intestines only are drawn. x100.
5. Section of the intestinal wall in the fore part of the body, with the chloragogene cells there are branched pigmented cells, chl; ei – ciliated intestinal epithelium, s – blood lacunes. x380.
6. Section of the epithelium of the pharynx; between the epithelial cells there are branched pigment cells. x380.
7. Transversal section of the body wall. x380
8. Section of the body wall in the clitellar segment; from a specimen approaching maturity. x360
9. Horizontal section of the cephalic lobe: cs – sense cells. x380
10. The four chaetae of a bundle in a posterior segment, isolated by means of caustic potash. x380
11. Longitudinal vertical section of the 6th segment, showing the body cavity filled by unicellular glands gl. x250
12. Longitudinal vertical section of the 10th segment, showing th cluster of granulated cells, x, and the large dark pigmented cells, pg, which lie around the bundles of chaetae. x250
13. Longitudinal section through the ventral bundle of chaetae in a posterior segment. x250
14. Three lymph cells in the coelome. x380
15. The right nephridium of the 15th segment, with the neighbouring bundles of chaetae. Combined figure from two sections. x250
16. Reconstucted sperm duct of the right side. p – pore, a – bulb (drawn as semi-transparent), in which the prostatic glands bb open; c – fusiform swelling of the duct; d – loop surrounded by the glands e; in – funnel. x130
17. Reconstructed spermathecae as a transverse section (from a series of transverse section), prs – expernal pore; drs – duct; rs – cavity of the spermathecae, ars – its appendages. x130
18. Anoplophrya sp? parasite in the intestine of Melanenchytraeus. x380
19. Parasitic cysts from the intestine of Melanenchytraeus; a – entire cyst; b – longitudinal cut cyst, showing its content of nucleate clear globules

Mesenchytraeus solifugus anterior.png
Ventral and lateral view of twelve anterior somites of Mesenchytraeus solifugus (Oligochaeta: Enchytraeidae). st – spermathecal pore at IV–V; ♂ – male pore; ♀ – female pore.