JOHNSON: POLYCHAETA OF PUGET SOUND REGION. 403 
As regards the so-called ‘‘branchiae” of Euphrosyne , it was long 
ago pointed ont by Clapardde (’68, p. 420) that functionally these 
are no branchiae, bnt probably glands, which furnish the slime with 
which the animal is more or less coated. I have recently had an 
opportunity to examine these structures in a young specimen of 
E. aurantiaca and compare them with the functional branchiae of 
Eurythoe cal if arnica, both in situ and freshly abcised from the liv¬ 
ing animal. While the branchiae of Eurythoe are richly vascular, 
the organs of Euphrosyne show not the slightest trace of blood¬ 
vessels, although almost as transparent as those of Eurythoe. On 
the other hand, these gill-like structures are richly beset with gland¬ 
ular cells, and there cannot be much doubt that they furnish a part 
or the whole of the mucus with which the setae are usually enslimed. 
The relationship of Euphrosyne to Eurythoe is undoubtedly close; 
many authorities place them in the same family. We may therefore 
legitimately conclude that here we have homologous structures that 
•have undergone a change of function; and the term “branchia,” 
applied in a morphologic sense, is not a misnomer, although perhaps 
liable to be misleading 
Study of sections of specimens of Euphrosyne aurantiaca and 
Eurythoe calif or nica, fixed in aceto-sublimate and stained with 
haemalum, shows less difference in the structure of the gills than 
would appear to exist from examination of the structures in the liv¬ 
ing or fresh condition. Both, indeed, contain blood-vessels or struc¬ 
tures functioning as such. In Eurythoe the presence of a vascular 
loop is very evident, but in Euphrosyne I have not been able to 
detect a loop, or in fact anything more than a cleft in the tissue 
sometimes empty, sometimes filled with coaguliun. This seems to 
/ 
be a lymph space connected with the body cavity. In both species 
the walls of the gills are thick, but thicker in Euphrosyne than in 
Eurythoe. The branchiae of Euphrosyne contain an axial strand of 
muscle fibres. Their surface is ciliated. 
Syllidae. 
20. Pionosyllis elongata sp. nov. PI. 6, figs. 67-70. PI. 7, 
fig. 71. 
Form slender, becoming much elongated with age; 140-200 so¬ 
mites; diameter nearly uniform the entire length, tapered slightly 
towards head and tail; intersegmental furrows are deeply incised ; 
somites average two and one half times as broad as long. 
