1909.] NATURAL SCIENCES OF PHILADELPHIA. 325 



setae appendages differing in form. S. singalisetis Grube, from the 



Philippines, also belongs to the subgenus Ehlersia, but has only four 



eyes. 



Pionosyllis typica sp. nov. PI. XV, figs. 5-7. 



Form moderately slender, widest in the region of the gizzard, from 

 which it tapers regularly to the caudal end. The well-extended and 

 complete type has 96 segments and is 31 mm. long and 1.2 mm. in 

 diameter at XXV. 



Prostomium small, somewhat sunken into peristomium, about one 

 and two-thirds times as wide as long, the greatest width posterior, 

 the sides and front broadly and regularly rounded. Eyes two pairs, 

 dark brown, small, anterior pair close to lateral border and about 

 midway of length of prostomium; posterior pair little more than one- 

 half diameter of anterior and slightly behind and within them. A 

 pair of faint ridges run from the posterior eyes to the posterior border 

 of the prostomium, nearly completing with the eyes a V-shaped figure. 



Palps completely separated to base, bent somewhat ventrad, broadly 

 triangular with rounded angles, about as long as prostomium and 

 basal width about two-thirds length. Median tentacle arising between 

 posterior eyes, about one and one-fourth times as long as prostomium 

 and palps, slender and slightly tapered, divided into about twenty- 

 four articles, distinct distally but obscure toward the base, not strongly 

 moniliform. Lateral tentacles similar, arising from a slight depression 

 just anterior to anterior eyes, nearly three-fourths as long as median 

 and reaching nearly as far, divided into nineteen or twenty joints. 

 Mouth rather large with prominent crenulated lips. 



Peristomium short and partly crowded beneath prostomium, but 

 visible for entire width of dorsum. Tentacular cirri similar to tentacles, 

 the dorsal slightly exceeding median tentacle in length, with about 

 twenty-six joints; the ventral somewhat shorter, with twenty joints. 

 Body segments nearly terete, remarkably regular but separated by 

 shallow, inconspicuous furrows ; except for a few short anterior ones they 

 are half as long as wide or more. From the maximum width at the end of 

 the first fourth they taper regularly to the pygidium, which is a small 

 ring and bears one of a pair of cirri as long as the last nine segments 

 and resembling the posterior neurocirri in being scarcely articulated. 



Parapodia (PI. XV, fig. 5) situated at ventral level of body, well 

 separated throughout, slender, rather conspicuous in ventral view but 

 largely concealed from the dorsum. The neuropodia are slightly com- 

 pressed and taper slightly to the bluntly rounded and rather abruptly 

 contracted end, which is divided into two small lips separated by a 



