NO. 22G3. ^TEW AFRICAN EARTHWORMS— SMITH AND GREEN. 



149 



wall at 13/13. The posterior one joins the ventral wall at about the 

 middle of 13 and the dorsal wall at 13/14 and probably is septum 

 12/13, or possibly 11/12 and 12/13 combined. 



The oral end of the alimentary tract is somewhat protruded and 

 has thin walls. In the third and fourth somites the dorsal wall has 

 a heavy mass of glandular and muscular tissue. The esophageal 

 region in 5-7 has relatively thin walls and is followed by two power- 

 ful gizzards, one each in 8 and 9 (fig. 2). Posterior to the gizzards 

 the lumen is large and the walls rather thin and highly vascular for 

 the next three or four somites and then the ordinary intestinal char- 

 acter is assumed. 



The two gizzards are decidedly more distinct than is indicated in 

 figure 2, which shows them lying in a position oblique to the long 

 axis, and does not well show the marked constriction at the union 

 of the septum 8/9 

 with the wall of the 

 esophagus, which is 

 shown bv sections. 

 The muscular layer 

 is not entirely absent 

 at the constriction, 

 but is reduced in 

 thickness to not over 

 one-eighth of that 

 near the middle of 

 either gizzard. 



Definite " hearts " 

 are present in 6 and 

 7, and four pairs 

 posterior to the sep- 

 tum 7/8 are assumed to belong to somites 8-11 (fig. 3). Organs arc 

 assumed to belong to any particular somite to which the hearts with 

 which they are associated are thus assigned. 



The worm is meganephric and apparently the first nephridia are 

 in the fourth somite. The nephridia associated with the "hearts" 

 of 8 and 9 seem quite certainly to be connected with the nephridio- 

 pores of 8 and 9, although the latter one is far removed from its pore 

 because of the displacement of the septa. Nephridia are present in 

 10, but the nephridiopores have not been located. They are absent 

 in 11 and 12, present in 13, absent in 14, and present in the follow- 

 ing somites. 



Two pairs of spermaries and of spermiducal funnels are con- 

 tained in paired sperm vesicles in 10 and 11, respectively (fig. 3).. 



Fig. 3.— Stngenodrilus lamuensis. Longitudinal section ke 

 constructed from several sections passing through the ovi- 



DUCAL PORE AND THE PROSTATE GLANDS. X23. ft, HEART; od p, 



oviDUCAL pore; oy, ovary; p, prostate gland; st, section 



THROUGH SACCULAR PART OF SPERMATHECA; S V, SPERM VESICLES 



sy, spermary; 8, 9, etc, numbers of somites. 



