THE NEMERTINES OF MILLPORT AND ITS VICINITY. iy¢ 
very light flesh colour. The proboscis, readily extruded, is also of a delicate pink 
colour. The animals very readily break up, more readily than any other Nemertines 
met with at Muillport. 
The cephalic grooves are two on each side, an anterior and a posterior; and each 
eroove extends on both dorsal and ventral surfaces (v. figs. 9,10). Dorsally the anterior 
grooves run transversely, nearly meeting in the middle line, and giving off a number of 
small secondary grooves which run in an anterior direction at right angles to the main 
groove ; the posterior grooves run very obliquely backwards and meet in the middle 
line. Ventrally, the anterior grooves are continued transversely, meeting or not in the 
middle line, with secondary grooves of the same description as those on the dorsal 
surface, and a dimple nearly half-way between the lateral margin and the median line ; 
the posterior grooves run transversely, with a slight inclination forwards, but do not 
meet. 
The above description corresponds in most points with that of MacInrosu, except 
that this author neither figures nor describes any extension of the posterior grooves on 
the ventral surface. JouBIN (7) criticises MacInrosu (“la figure donné par MacInrosu 
est assez défectueuse pour ce qui est des sillons”), and states (8) ‘“‘je n'ai point vu les 
sillons secondaires que figure MacIntosn.” He describes (8) the anterior dorsal grooves 
as being together V-shaped, like the posterior, but his figure shows that they run for the 
most part almost transversely, each, however, bending in a posterior direction near its 
inner end; the ventral grooves of his specimens seem to have been entirely different 
from the Scotch forms, and, according to his figure, produce by their bifurcations and 
reunions the appearance of a number of somewhat rhomboidal or irregular areas on this 
surface. Butraeur (8, 5), as for A. lactifloreus, does not mention the grooves. It would 
seem therefore, on the whole, that both the course of the main grooves and the presence 
of secondary grooves are liable to very considerable variations. 
The eyes in my specimens were numerous, and distributed somewhat irregularly 
near the lateral margins of the head, mostly in front of the anterior groove. In one 
specimen there were thirty-four on the left side and about as many on the right; in 
another, there were fifteen on each side. The larger eyes are irregular aggregations of 
pigment, apparently formed: by the fusion of smaller eye-spots. 
Other authors give diverse accounts of the eyes. MacInrosu states that they are 
about twenty-three in all; Jounin (7) that they are thirty-five to forty-five on each side, 
or, again (8), eighteen to twenty-five on each side. BtreEr (3) states that they are 
‘ziemlich regelmissig zweireihig angeordnet,” and, in the Zierreich, includes this feature 
in the diagnosis of the species (‘‘ mit vielen Augen, die in 2 Reihen angeordnet sind”). 
From what has been said, however, it would appear that neither the number nor the 
arrangement of the eyes present sufficient constancy to permit of their being used as a 
specific distinction. 
The basis of the stylet is of a regular oval shape, and the stylet itself may project 
behind it (fig. 11). The distal free portion of the stylet is equal in length to the basis. 
TRANS. ROY. SOC. EDIN., VOL. XLVILI. PART IT, (NO. 1). 3 
