34 



COE 



rangement of 

 ocelli. Dorsal 

 surface. X 6. 



Ocelli. Numerous minute eyes are arranged in two groups on each 

 side (fig. 7). Of these, an anterior group of 12 or more small pig- 

 ment spots are scattered along each side of the antero-lateral margin, 

 while about as many more occupy an irregular cluster on 

 each side just in front of the brain. These latter ocelli 

 are usually well separated from the anterior, or mar- 

 ginal groups. 



Proboscis. Proboscis of medium size (as in Amphi- 

 porus}, slightly yellowish, and usually everted when the 

 animal is killed. The extruded proboscis is short and 

 thick with an unusually slender posterior chamber. The 

 armature (pi. vii, fig. 7) consists of a small, slender, 

 sharply pointed central stylet, and with either 2 or 4 



FIG. 7. Par- Couches of reserve stylets. The basis of the central 

 anemertes per- . . .. . .. . . . , 



O stylet is very small and slightly enlarged posteriorly ; 



ifne of anterior tne reserve stylets are slender and sharp like the central 

 portion of body one, and commonly number from 6 to 10 in each pouch, 

 to show the ar- When four pouches are present the number of stylets in 

 each is as great as when there are only two pouches. 



The mouth and proboscis open together, but the 

 rhynchodaeum is short. The proboscis sheath reaches 

 about three-fourths the length of the body, or sometimes more than 

 three-fourths. In each of four specimens sectioned there were 14 con- 

 spicuous nerves in the proboscis. The proboscis has a remarkably nar- 

 row ring of gland cells on the periphery near the posterior end of the 

 basis of the central stylet. 



A crowded mass of multicellular glands occupies the anterior por- 

 tion of the head. The anterior ones open on the tip of the snout. In 

 the brain region they open mostly on the lateral surfaces of the body, 

 while farther back, and in the esophagal region, they assume the 

 character of sub-muscular glands. No difference in appearance is no- 

 ticeable between the cephalic glands and those in the esophagal region. 

 They are present in the esophagal region only about as far back as 

 the openings of the nephridia. Throughout their course they open to 

 the exterior (by innumerable ducts which pass through the muscular 

 and basement layers) on the ventro-lateral aspects of the body. 



Alimentary canal. A pair of slender branches of the intestinal 

 caecum reach forward nearly to the brain commissures and lie well 

 above the lateral nerve cords. At about the point of the nephridial 

 openings these branches pass ventrally and occupy a position beneath 

 the esophagus. Another pair, coming forward from behind, take 



