NEW KORTH AMERICAN EARTHWORMS 163 



branched. The blood plexus of the middle layer of the esophageal 

 wall has branches extending into many of the diverticula. It seems 

 probable that the function of this part of the alimentary tract is 

 similar to that of the organs known as calciferous glands in some 

 kinds of earthworms, and, since in some closely related species de- 

 scribed in this paper this part of the esophagus becomes more highly 

 modified into a definite calciferous gland, it seems advisable to apply 

 the same term to this part of the esophagus in the present species. 

 The intestine begins in 19 but does not attain maximum enlargement 

 anterior to 21. A typhlosole is present but is not large. 



The study of the circulatory system has added to the facts given 

 in the preliminary report (Smith, 1897) but does not provide ma- 

 terial for a complete description. A dorsal vessel and ventral vessel 

 are present as in other earthworms. No lateral neural or subneural 

 vessels were found, a condition commonly reported in INIegascolecidae. 

 Because of incompleteness in the series of sections available, the an- 

 terior and posterior extremities of the supra-esophageal vessel were 

 not located. Enlargements of the vessel and communications with 

 the plexus of the esophagus are present in 9-14. The parts of the 

 vessel that connect these enlargements and pass through the septa 

 are inconspicuous. Paired dorso-esophageal hearts are present in 

 10-13, where their chief dorsal communication is with the supra- 

 esophageal vessel. In each of somites 7-9 is a pair of smaller dorsal 

 hearts. The micronephridia in the specmiens examined seemed to 

 be present in somites beginning with the second one, and the number 

 is somewhat variable, but there are approximately seven on each side 

 of the somites. There is also a pair of meganephridia in each of the 

 somites in the posterior part of the worm. 



The reproductive organs are similar to those commonly found in 

 the genus. Spermaries and spermiducal funnels are paired in each 

 of somites 10 and 11 and the sperm ducts of either side unite in 16, 

 and the common duct thus formed opens into the proximal end of 

 the prostate duct of the same side. Paired sperm sacs in 11 and 12 

 open through septa 10/11 and 11/12 into the cavities of 10 and 11, 

 respectively. The openings are near the lateroventral esophageal 

 wall. One pair of tubular prostate glands is present in 18. The 

 glandular part of each is long, tubular, and contorted and occupies 

 considerable space. Each prostate duct has a length about equal to a 

 half of the diameter of the worm and is an outlet not only for gland 

 secretions but also for sperm cells. Ovaries and oviducal funnels are 

 paired in 13 and oviducts in 14. There is a pair of spermathecae 

 in each of somites 8 and 9. In the sexually inactive specimens avail- 

 able for study the spermathecal ducts are very short, and each has 

 on the anterior lateral wall a diverticulum with thick irregular walls. 



