438 PROCEEDINGS OF THE ACADEMY OF [June, 



and consequently often injured and imperfect; inner laterals arise just 

 dorsad of the eyes, outer laterals just cephalad. 



Peristomium about as long as the prostomium laterally, but else- 

 where shorter; dorsally it presents a shallow bay affording an inset 

 for the bases of the median and inner lateral tentacles, laterally a sub- 

 ocular lobe which is united with the prostomium and partly conceals 

 the eyes, and ventrally a pair of lobes which conceal the mandibles 

 and are separated from one another and from the lateral lobes by 

 emarginations. Tentacular cirri long and slender, reaching slightly 

 l)eyond the anterior extremity of the palpal lobes and, when reflexed, 

 caudad to somite VII. 



The second somite is about ^ the lateral length of the peristomium, and 

 f the length of somite V, to which the lengths of the somites increase, 

 beyond which they decrease through the branchial region, and then 

 regain their maximum size, which is retained until they finally fall 

 off to the caudal end. The body as a whole is somewhat depressed, 

 most so in the branchial region, strongly convex dorsally in the pre- 

 branchial and caudal regions, but ventrally flattened throughout, with 

 a strongly marked neural groove. The two long tapering caudal cirri 

 equal the last 9 segments in length. 



The first pair of parapodia are on a level with the ventral surface, 

 and succeeding ones gradually rise until the normal position about mid- 

 way between the dorsum and venter is attained by X or XI, and main- 

 tained throughout the branchial region and beyond; then they sink 

 again to the ventral level posteriorly. The typical structure is reached 

 at about the 5th or 6th parapodium. Xeuropodium short, little tap- 

 ered, truncate and somewhat bilobed. Xeuropodial cirri with en- 

 larged, tumid bases about equal to the neuropodia, bearing small 

 lobe-like terminal pieces about -j as long. Notopodial cirri slender,, 

 with a slight sensory swelhng on the ventral side near the base, about 

 3-4 times the length of the neuropodimn and nearly long enough to 

 reach the median line of the back. The first parapodium consists of 

 a minute setigerous lobe, a long notopodial cirrus reaching the anterior 

 border of the peristomium, and a much stouter basall}' swollen neuro- 

 podial cirrus of about half this length. Toward the posterior end the 

 parapodia become more tapering in continuation of the body outhnes, 

 and scarcely project from the surface; the neuropodial cirri lose the 

 basal enlargement, taper regularly, become more prominent and assume 

 a more caudal position ^vith relation to the foot; the notopodial cirri 

 become relatively shorter, the extreme posterior ones being about 

 twice as long and half as thick as the ventral, and the sensory elevation 

 more prominent. 



