TUBE OF PANTHALIS. 343 



In this paper I do not profess to have gone mmutely 

 into details of the anatomy of Panthalis, but in the course 

 of my observations, one or two points of interest have come 

 before me, and a brief reference to them may be usefuL 



The sight of the animal is evidently very good, and a 

 remark as to the structure of the organs of sight will be 

 interesting. The eyestalks, as also the cephalic mass to 

 which they are attached, are brownish-red in colour, and 

 have at their tips a rounded papillated appearance. Each 

 eyestalk is faced with a clear lens, the curve of which is 

 occasionally somewhat acute, though this seems to vary, 

 and possibly the animal may have some means of adapting 

 it to circumstances. 



The structure and action of the Proboscis also deserve 

 a passing note. As is usual in annelids, this organ is very 

 often protruded in the act of dying, and thus affords an 

 opportunity for observation of its action. In Kinberg's 

 figures of Panthalis and Eupompe the proboscis is shown 

 protruded, but the peculiar structure of this organ is 

 hardly noticeable. My specimens agree more closely with 

 his figure of Eupompe than with that of Panthalis. As 

 described by Claparede (Les Annelides Chetopodes du Golfe 

 de Naples, 1868) the proboscis is divided into two parts, 

 a longer inferior portion consisting of a cylinder of 

 somewhat ordinary form, and a short superior portion, 

 which carries the jaw^s and is fringed with papillae, the 

 central ones of which, both dorsally and ventrally, are 

 considerably elongated. The dorsal one being about f% of 

 an inch long (in my large specimen) forms a tentacle. 

 The action of the organ is a double one, and as follows : — 

 the lower part only of the proboscis is first protruded, 

 either for the purpose of burrowing in the mud (as I have 

 seen it used) or in search of food. In the latter case, the 

 central dorsal tentacle attached to the margin of the 



