BY WILLIAM A. IIASWELL, M.A., U.SC. 751 



behind, a decrease in breadth taking place suddenly at about the 

 twentieth segment : the total number of the segments is about 

 forty. The colour is light i^ed ; the hinder part crimson. 



The head is broader than the immediately succeeding segments. 

 Immediately in front of the mouth on the ^entral surface are 

 inserted a pair of thick longitudinally folded palpi which are three 

 times the length of the branchiae. 



Thei-e are two i)airs of eyes ; the anterior pair are large, of sub- 

 triangular outline, placed close together one on either side of the 

 middle line of the dorsal surface of the head. The second pair 

 which ai'e external to, as well as behind the first, are mere specks 

 of black pigment. The head is surrounded by a circlet of about 

 twenty-five short cylindrical green branchise, and external to those 

 at the sides and behind, by two fan-like fasciculi of very slender 

 setfe, about forty on each side ; these extend nearly as far 

 forward as the extremities of the palpi ; they are simple and hair- 

 like, but transversely jointed. The second and all the following 

 segments have short parapodia armed with about half-a-dozen to a 

 dozen slender setse similar to those surrounding the head, and 

 arranged in two fasciculi ; on the ventral aspect of the parapodium 

 is a dark-coloured, stouter, hook-like, seta considerably shorter 

 than the others, likewise transversely jointed. The papillae are 

 numerous, frequently as long as the setae, with a long and slender 

 hyaline stalk and a head which varies in form, but is usually long 

 oval or spindle-like. 



The anterior lai'ger pair of eyes are complex, with a thick^ 

 darkly pigmented choroidal capsule, lined internally by a thick 

 retina, composed of elongated radially disposed cones : they are 

 embedded in the substance of the cerebral ganglion. 



Opening just behind the head on the dorsal surface near the 

 lateral margin, are a pair of very long narrow cylindrical glands 

 which extend throughout a considerable portion of the body. They 

 have delicate walls and are filled with cells with colourless walls 



