yo coE 



A section through the esophagal region shows that the outer longi- 

 tudinal muscular layer of the body wall is particularly thick, and that 

 the esophagus is unusually small. The other layers are as in most 

 species of the genus. 



The lateral blood lacunas break up in the esophagal region into 

 numerous thin- walled vessels, or spaces, which surround the lateral and 

 ventral walls of the esophagus. 



Nephridia. — The nephridia extend through the anterior ^ of the 

 esophagal region, as a single profusely branched tubule on each side. 

 All the branches of the main canal are small, and lie in close connec- 

 tion with the walls of the blood spaces about the esophagus. The 

 efferent ducts are very numerous, but minute. They open on the 

 dorso-lateral aspects of the body, usually not far above the lateral mar- 

 gins. In a single instance one of the efferent ducts was found to 

 open beneath the lateral margin, but this must be looked upon as ab- 

 normal. In several instances two efferent ducts lay close together on 

 the same side, but in such cases one originated much nearer the ven- 

 tral side of the esophagus than did the other. The actual number of 

 efferent ducts counted in one medium-sized individual was 17 on one 

 side, and 24 on the other. 



Reproductive organs. — The pouches containing the sexual products 

 when mature become so voluminous as to occupy more than half the 

 entire space within the body walls. In July, when the genital prod- 

 ucts are fully ripe, the ducts leading to the exterior are completely 

 formed some little time before the elements are discharged. Each 

 pouch has a single duct opening into a funnel-shaped depression through 

 the epithelium on the dorso-lateral aspect of the body. The opening 

 into the cavity of the ovary is on the surface of a broad papilla formed 

 of long columnar cells, a portion of which bend inward to guard the 

 opening. The ducts often have a somewhat tortuous course, and are 

 likely to broaden out considerably in passing through the circular mus- 

 cular layer. 



Size. — The length of the largest individual observed was about 300 

 mm., and its width 6 mm. 



The species is named in honor of Prof. A. E. Verrill, of Yale 

 University, who, more than any one else, has helped to bring the 

 American species of Nemerteans into orderly arrangement. 



Stimpson ^ briefly describes from Bering Strait a species of Cere- 

 bratulus ( C ifnpressus = Alicrura impressa) which bears a superficial 

 resemblance to the above. Stimpson's species, however, was flattened, 



'Proc. Philadelphia Acad. Nat. Sci., p. 160, 1857. 



