1917] Essenherg: New Species of Amphinomidae 69 



Branchiae occur on all setigerous segments, usually six pairs on 

 a segment, but there may be only five pairs on the few extreme ante- 

 rior segments, and seven pairs on the median segments. Each gill- 

 trunk consists of a stem dividing dichotomously several times. The 

 gills vary in size, the individual projections ranking from four to 

 eight in number on each gill-trunk (pi. 5, figs. 31, 32). 



The notopodial setae (pi. 5, figs. 26, 28, 29) are arranged in a long 

 palisade of two rows along the entire length of the gill-series. They 

 all are hollow, calcareous, translucent and yellowish-white. They 

 are comparatively short, some projecting slightly beyond tips of the 

 gills. The serrated bifid dorsal setae (pi. 5, figs. 28, 29) are narrow, 

 enlarging near the place of forcation. Both forks are slightly bent, 

 strongly serrated along the inner borders, and are covered with fine 

 asperities. The serrated dorsal setae are more numerous on the ante- 

 rior portion than on the rest of the body. The dorsal setae of the 

 second row (pi. 5, fig. 26) are of the simple form, incompletely bifid, 

 one of the forks being much longer, about three times the length of 

 the shorter fork, with almost straight, smooth tips. The neuropodial 

 setae (pi. 5, figs. 27, 30) arise in several rows from an elliptical area. 

 They are similar to the smooth dorsal setae but are much stouter and 

 longer than the latter. The length of the ventral setae varies, those 

 in the dorsal part of the fascicle being the longest (about 1 mm.), 

 the setae decreasing in length as they proceed ventrad. 



Comparison. — The species resembles somewhat Euphrosyne diimosa 

 Moore (1911), but differs from it in the lesser number of gill-trunks 

 and in the shape of the setae. Euphrosyne dumosa has 10-11 pairs 

 of branchiae on each segment ; E. kyllosetosa, 6-7 pairs. The setae 

 differ considerably in the two species. The distal ends of the noto- 

 setae as well as of the neurosetae are more slender in E. dumosa than 

 they are in E. kyllosetosa, and the shorter fork of the non-serrated 

 setae is very short, almost rudimentary, in E. dumosa. Other minor 

 differences may be found in the shape of the branchiae and in other 

 characteristics. 



The two specimens, type and cotype, were collected between tide- 

 marks from drifting kelp near La JoUa, California, and were kindly 

 presented to me by the collector, Mr. H. 0. Falk. They are now in 

 the annelid collection of the University of California in Berkeley. 

 Five specimens of E. Umhata Moore have been given to me by the 

 same collector and are now in the annelid collection of the Zoological 

 Museum of the University of California at Berkeley. They were 

 collected on December 4, 1915, from kelp holdfasts off La Jolla. 



