i168 Mr. H. N. Moseley on Pelagonemertes Rollestoni. 
in picric acid. The inner longitudinal layer consists of stout 
bands of fibres running parallel to one another. The outer 
circular fibres are far less developed, and are not gathered 
into bundles, but cross one another slightly obliquely in their 
transverse course, forming a slight meshwork over the longi- 
tudinal fibres. 
Beneath the muscular tunic and between its meshes the 
body mass is filled up with a gelatinous hyaline structureless 
matter, imbedded in which lie the viscera and the muscles 
attached about the orifice of the sheath of the proboscis. 
Internal muscles, except those referred to, were not observed. 
No eyes or other sense-organs were found; and ciliated sacs 
were not seen. 
From the circumstance of the only specimen of Pelago- 
nemertes having been much lacerated, and from the animal 
not having been dissected, it will of course require further 
examination. In the specimen as procured there was a deep 
constriction of the body at about the junction of the first with 
the second fourth of its length. This, it appeared pretty 
evidently, had been caused by the meshes of the net. The 
posterior extremity was somewhat injured, and its form may 
not be quite correctly given. Ciliated sacs may be present ; 
and the structure of the proboscis might throw light on the 
affinities of the animal. 
The form of the digestive system is the most remarkable 
feature about Pelagonemertes, in its close resemblance to that of 
Dendrocela. In other respects Pelagonemertes is thoroughly 
Nemertine in structure, being merely modified for pelagic 
existence. It is remarkable that the gelatinous hyaline mass 
of the body is not tegumental in character, but apparently 
homogeneous with internal structures. 
The occurrence of a peculiar burnt-sienna colour in many 
very different pelagic animals is remarkable. With many 
the colouring may be explained as protective resemblance to 
the oceanic seaweeds. or its occurrence in others, such as 
Salpa and Pelagonemertes, in an otherwise hyaline body, there 
may be some common cause, possibly also protective. 
Diagnosis of the Genus Pelagonemertes, H. N. M.: Body 
leaf-shaped, gelatinous, hyaline. .The anterior extremity of 
the body broad and abrupt, the posterior narrowed to a point. 
The digestive canal with thirteen pairs of lateral ramifications, 
as in Dendroceela. Integument thin and hyaline, with a thin 
muscular tunic immediately beneath it, consisting of external 
circular and internal longitudinal fibres. The animal free- 
swimming, oceanic. 
