Annelida of the Bermudas. 619 



Hemisyllis, gen. nov. 



Similar to Eusi/llis, but with the large palpi united together for 

 about half their length in front of the head. Antennae, tentacle, and 

 anterior cirri long and beaded, as in SylUs\ oesophagus straight, with 

 the front edge serrulate ; median tooth submarginal. Setae few and 

 simple, bidentate, without blades, 



Hemisyllis dispar, sp. nov. 



A small species with broad head and palpi, the lobes of the palpi 

 projecting forward from the swollen common base which looks like 

 a part of the head. 



Head large and broad, the anterior half nearly semicircular ; the 

 front margin well rounded, apparently coalescent with the palpi in 

 the middle ; sides most prominent posterior to the eyes ; posterior 

 margin broadly convex. Eyes 4, small, black, in a trapeze, the ante- 

 rior larger, not very close to the sides of the head ; the posterior are 

 very small, separated by about 4 diameters from the anterior ones. 

 Palpi very large and wide, their bases thick and swollen, united 

 together for about half their length, the front edge of the common 

 base convex between the separated free lobes, which are narrow- 

 ovate and obtuse. 



Tentacle, antennae, and all cirri are all similar in form, tapered and 

 strongly beaded with roimded annuli, which on the middle and dis- 

 tal parts are as long as wide, or even longer than wide, and elliptical 

 toward the end. The tentacle has about 20 beads and is about as 

 long as the head and palpi combined; the antennae are rather shorter, 

 with 18 beads. The upper tentacular cirri are longer and rather 

 stouter, with about 20 beads ; the lower are about f as long. The 

 first dorsal cirrus is longer than the tentacular cirrus and has about 

 22 beads; its length is about 1^ times the breadth of the segment; 

 second cirrus is about ^ as long, with 9 beads; third and fourth are 

 rather longer than the second, with 14 beads; farther back they 

 decrease rapidly, so that back of the stomach most of them are quite 

 short, mostly with only 2-4 beads. The ventral cirrus is papilliform. 

 Caudal end is lacking. 



The seta? are few, small, and short ; in the anterior region there 

 is, in each fascicle, only 1 small bidentate seta (without blade, in the 

 type), and 1 slender aciculum, with a small hooked tip, scarcely pro- 

 jecting. 



The oesophagus is long and slender, occupying 7 segments ; its 

 edge is denticulated with small, unequal, acute teeth ; median tooth 

 Trans. Conn. Acad., Vol. X. December, 1900. 



41 



