116 HETERONEREIS. 
with an auricular appendage near its base, whereas ven- 
trally it has a crenulated and lobulated border. The inferior 
ligula, about of the same length as the ventral lobe, boot- 
shaped, with a narrow horizontal process at its base, behind 
as well as in front; in the California-species the inferior 
ligula is more simple, without these processes, only with a 
boss at its upper border. The ventral cirrus slender, as 
» long as the inferior ligula, dorsally with a small 
bifurcated lamella, ventrally with a larger one, 
emarginated in the middle of its inferior border; 
in the California-species the dorsal lamella is 
simple, not bifurcated. As also is stated by Gra- 
vier the swim-bristles (fig. 5) have a slightly 
heterogomph shaft. Their knife-shaped terminal 
pieces have the dorsal border finely serrulated 
till at some distance from the distal end; their 
surface shows faint, parallel, longitudinal lines, 
except on the blunt top, that is furnished with 
some transverse ridges; the number of these 
SE = ridges increases by little and little in the more 
the epitocous upwards situated bristles of a fascicle, the superior 
body-region. Ones even being wrinkled over their total surface. 
As the proboscis was not protruded nothing can be said 
about the arrangement of the paragnathi; however Gra- 
vier has stated in the California-species groups of conical 
denticles upon both its regions. Therefore these species must 
belong to one of the subgenera Nereis, Eunereis, Cerato- 
nereis or Neanthes, unless they represent probably a hitherto 
unknown genus. 

Leyden Museum, January 1911. 
Notes from the Leyden Museum, Vol. XX XIII. 
