1917] Essenberg: Neiv Species of Amphinomidae 67 



ually attenuating toward the posterior end and with both ends 

 obtusely rounded. The dorsal surface is almost straight and only 

 slightly arched. The ventral surface is strongly convex. The length 

 of the body is 55 mm., the width, in the widest part of the body (about 

 segments 29 and 30), 13 mm. The segmentation is well shown on the 

 dorsal and the ventral surfaces, as well as on the vertical sides. The 

 number of segments is 66. The caruncle (pi. 5, fig. 18) is coalesced 

 with the prostomium. It is broad and smooth without any grooves 

 and extends to the fourth segment. It has one short median tentacle. 

 The posterior end of the caruncle is narrow and cleft. The prosto- 

 mium bears two pairs of cirri. No eyes are visible on this specimen. 

 The buccal region extends to the fifth segment (pi. 5, fig. 19). The 

 cirri are spirally constricted. The parapodia (pi. 4, fig. 17) are made 

 up of two widely separated rami. The ventral ramus bears a spirally 

 constricted cirrus and a fascicle of comparatively short setae about 

 one-half the length of the cirri (pis. 4 and 5, figs. 17, 19). The ventral 

 setae (pi. 5, figs. 22, 23) are light yellow, hollow, brittle, with a sub- 

 terminal prong, ending bluntly. The dorsal division bears a ramose 

 gill (pi. 4, figs. 15, 16, 17). The gill-branches increase in complexity 

 toward the median and posterior portions of the body. The dorsal 

 setae are of two types. One type (pi. 5, fig. 20) is strongly serrated, 

 ending bluntly; the other, very fine, straight, the distal end slender 

 and pointed, with very minute serrations above the prong (pi. 5, 

 fig. 21). 



Comparisons. — The worm was labelled as EurytJioe californica. 

 It differs from E. caUf arnica Johnson by the shape of the caruncle, 

 which is narrow and twisted in the latter species, with the prostomium 

 bounded anteriorly by a peculiar crescent-shaped margin. In Enry- 

 thoe spirocirrata the caruncle is smooth and broad. Further differ- 

 ences are evident in the setae, which are entirely different in the two 

 species. The ventral setae differ in shape, and the two kinds of 

 serrated dorsal setae present in E. spirocirrata are represented in 

 E. californica by perfectly smooth, straight setae without any serra- 

 tions. The cirri are spirally twisted in Eiirytkoe spirocirrata ; they are 

 straight in E. californica. Comparing the illustrations as well as the 

 specimens of both species, one can see at once the characteristic dif- 

 ferences. 



Eurythoe spirocirrata resembles E. pacifi.ca Kinberg more in gen- 

 eral appearance and in the shape of the body. It differs from the 

 latter in the broad shape of the caruncle, by the spirally twisted cirri. 



