462 WESLEY R. COE AND STANLEY C. BALL 
stricted laterally behind these fins and then broadened at the 
posterior end to form a well-developed caudal fin (fig. 1). Just 
behind the head is a short neck region which gives rise to a pair of 
slender appendages, cirri, or tentacles, in the males only. The 
length of the tentacles increases with sexual maturity; when well 
developed becoming more than twice as long as the width of 
the body. ‘The shape is well adapted for sluggish swimming in 
the depths of the ocean. The specimens available for study 
varied from 30 to 38 mm. in length and from 7 to 9 mm. in width, 
with a thickness of about 2 mm. after many years’ preservation 
in alcohol. Verrill (’92) however, states that the largest specimen 
when first seen by him was about 23 inches long and 3 inch wide. 
The fact that preservation in alcohol has reduced the body to 
about one-fourth its original bulk indicates the extremely gelat- 
inous consistency of the living animal. The females described 
as Hyalonemertes atlantica by Verrill (92) were from 20 to 38 
mm. long and from 33 to 11 mm. wide. 
Color. ‘The living animals are described by Brinkmann (17, © 
17a) as varying from red to orange red; the color being due to 
the contents of the intestinal cells. The margins of body are, 
consequently, colorless. This agrees with the color of one of 
Verrill’s specimens, which was seen by him shortly after preser- 
vation, and was salmon or pale orange colored. N. pelagica 
is, according to Cravens and Heath (’06), bright scarlet. All 
observers mention the great translucency of the body in this 
and related forms. : 
Habitat 
The seven specimens collected by the U. 8S. Fish Commission 
came from the North Atlantic Ocean at four stations between 
about 37° and 42° N. Lat., and 50° to 73° W. Long., the depth 
of water in this region being from 600 to 1700 fathoms. The 
recent studies of Brinkmann (17, ’17a) show that the worms 
are strictly bathypelagic, and that the species occurs throughout 
the entire width of the Atlantic Ocean between 35° and 64° N. 
Lat. at a depth of 500 fathoms or more. 
