﻿384 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 102 



ribbons to ridges, which are narrower than the intervals between. 

 The circular muscle bundles are here seen to best advantage. The 

 transverse slits between them are virtually very numerous pockets 

 directly beneath the thin skin, to which the coelomic fluid and con- 

 tents have access. 



Posterior attachment of the ventral retractors is to muscle bundles 

 3-4, 4-5, 3-5, from nerve cord; that of dorsals is to muscle 8 or some- 

 times 7, well in advance of the ventrals. Anteriorly the four retrac- 

 tors are in close contact forming a muscular trough in which lies the 

 esophagus. The lateral mesenteries of esophagus are apparent for 

 only a short distance posteriorly. 



The neplu'idia are slender, free, brown, and open about four muscle 

 bands laterally from the nerve and a short distance (varying with 

 contraction of longitudinal muscles) in front of the anus. In one 

 specimen they are full of eggs. In front of the broad nephrostome, 

 and also sometimes for a short distance back of it, is an area occupied 

 by papilliform outgrowths of the epithelium, the so-called Keferstein 

 bodies. They are either simple or branched (pi. 20, figs. 4, 5). 



In the relaxed type specimen the esophagus is very long, slender, 

 and anteriorly marked by the contractile vessel. The lateral mesen- 

 teries are inconspicuous and their posterior border has a muscular 

 strand continued upon the sides of the esophagus. The contractile 

 vessel is posteriorly densely papillated and its posterior end is con- 

 siderably behind the point where the esophagus becomes attached to 

 rectum. Just back of this point the esophagus has a special fixing 

 muscle (F) , which is anchored by a fork spanning the nerve cord well 

 in front of the attachment of the ventral retractors. The special 

 fixing muscle, F, sends a few strands to the rectum, which is here 

 closely attached to the esophagus. The intestinal spiral (60 to 62 

 single coils) is very long and sometimes reaches nearly to the end of 

 the body. 



Plate 20, figure 3, and plate 21, figure 3, show the relationship of 

 esophagus, rectum, and spindle muscle in the type and paratype. The 

 spindle muscle arises in front of the anus and after passing backward 

 through the intestinal spiral (which in the type extends to within 65 

 Eom. of the end of body) it sends off numerous branches, which are 

 attached to the longitudinal bands ventrally, laterally, and dorsaUy, 

 while a small strand continues to the posterior extremity. At the 

 point where the esophagus joins the rectum there are two sjmimetrical 

 lateral roots (S\ S^) attached in front of the dorsal retractors to the 

 first muscle bundle external to that from which the dorsal retractors 

 arise. There is no coecum. The wing muscles are fairly conspicuous. 



At the extreme posterior end of the body are fom* or five slender, 

 terete, fusiform bodies, which open close together (around the end of 



