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NEW NOKTH AMERICAN EARTHWORMS 173 



Dorsal pores are present posterior to the clitellum. Nephridio- 

 pores are very small and inconspicuous near the anterior margins of 

 tiie second and following somites. They are usually eight or nine 

 in number on each side of the few anterior somites of which sections 

 were studied. There is a pair of male pores on 18, laterad of the 

 penial setae and very near to them. They are borne on elevations 

 that are transversely elongated and are due in part to an increased 

 thickness and develoj^ment of the musculature of the body wall in 

 that region. Oviducal pores are paired on 14 and are slightly an- 

 terior to the ventral setae and midway between seta line a and the 

 median ventral line. There is but one pair of spermathecal pores, 

 and they are located at the anterior margin of 9 and near seta line h. 



Internal characters. — The septa 6/7-11/12 are strongly thickened, 

 12/13 less thickened, and other septa not thickened. The pharynx 

 has a thick muscular dorsal wall, and a powerful gizzard is present 

 in 5. A calciferous gland is present in 10-14. The enlargements 

 of the esophagus between the septa have numerous folds of the lining 

 layer reaching nearly to the middle of the lumen. These folds are 

 not quite so numerous and crowded as those found in Megascolides 

 ndchaelseni, and the glandular development is intermediate between 

 that found in the gland of that species and that in the gland in 

 M. americanus. The intestine begins at about 19. A typhlosole is 

 present. Dorsal, ventral, and supra-esophageal vessels are present 

 and also hearts in 7-13, but owing to the fact that the longitudinal 

 vessels were in part included in the unsectioned part of the worm 

 a complete study has not been made of all the connections of the 

 various hearts with the longitudinal vessels. The data obtained in- 

 dicate that the relations are like those found in the other species 

 here described. The nephridia are of the micronephridial type, with 

 about eight on each side of somites beginning with the second one. 

 The pores and ducts are very small and difficult to trace even in 

 sections. 



Spermaries and spermiducal funnels are paired in 10 and 11. The 

 sperm ducts of either side are not united but continue their courses 

 closely parallel to each other. They reach the wall of the prostate 

 duct near its union with the gland. Here they enter the wall, which 

 they follow until they open into the lumen of the duct at about 

 one-third of the length of the duct from its proximal end. Paired 

 sperm sacs in 11 and 12 open through septa 10/11 and 11/12 into 10 

 and 11, respectively, in close proximity to the esophagus. One pair 

 of tubular prostate glands is present in 18. The glandular part is 

 long and contorted. Ovaries and oviducal funnels are paired in 

 13 and oviducts in 14. No ovisacs were recognizable. There is but 

 one pair of spermathecae, and they are of large size in somite 9. 



