i8o' cos 



are often irregularly joined together, so that the individual ocelli cannot 

 be distinguished, appearing rather as a row of scattered pigment masses 

 on each side. In microscopic sections the eyes appear deep blue in 

 color. 



In internal organization the species shows many deviations from 

 most other members of the genus although it is evidently closely related 

 to L.Jlavescens. It presents a number of interesting anatomical pecu- 

 liarities, which are noted below. 



Body Walls. — At the point where the posterior esophageal cavity 

 enters intestine, the circular muscular layer abruptly becomes less than 

 half as thick as it is farther forward, and allows the outline of the body 

 to become much wider and more flattened. In the esophageal region a 

 cross section is but little wider horizontally than vertically, but in the 

 intestinal region it is nearly twice as wide. Tliis is due to the reduc- 

 tion of the circular muscular layer. 



Extensive cephalic glands (p1. xxii, fig. i, cgl) reach inward 

 almost to the blood lacunae in the anterior portions of the head, but do 

 not extend behind the brain except on the ventral side, where they reach 

 as far as the posterior ends of the cerebral sense organs. Beneath the 

 rhynchodaeum is a conspicuous canal (a) which passes forward and 

 joins the rhynchoda^um immediately where this opens on the ventral 

 side of the tip of the snout. This canal is apparently the common duct 

 of the cephalic glands which lie beneath the brain, for it originates pos- 

 teriorly in a large cluster of these glands. Yet in no other species of 

 Nemertean has such a well-developed duct been obsen^ed. Unfortu- 

 nately the character of its lining is obscured by the secretions which it 

 carries, so that its precise nature is not absolutely certain. 



The glands of the cutis (p1. xxii, fig. i, cugl^ are extremely abun- 

 dant in the head. They extend inward to the circular muscular layer 

 throughout the whole intestinal region. Back of the mouth they sink 

 gradually through the cutis and deeper into the external longitudinal 

 muscular layer. In the region of the nephridiopores they have passed 

 completely through this layer in a narrow area on the dorsal and on 

 the ventral side, and have come in contact with the outer border of the 

 circular muscular layer. Farther back the region in which the glands 

 reach inward as far as the circular muscle becomes increased, until at 

 the beginning of the intestinal region it extends along the whole cir- 

 cumference except in the vicinity of the lateral nerves. Throughout 

 the length of the intestinal region these glands continue to border the 

 whole surface of the circular muscles, except in the immediate position 

 of the lateral nerves. Perhaps in no other member of the family 



