[McMURRICH] PLANKTON OF BRITISH COLUMBIA COAST tht 
with it by Schneider! and Vanhdéffen.2 It has also been taken off 
the north coast of Ireland and off East Spitzbergen. It was abundant- 
ly present in the plankton now being considered, but unfortunately 
the formalin, in which the material was preserved, produced complete 
disintegration of the colonies into their constituent parts, and circum- 
stances did not permit of the study of the material while still alive. 
The form of the Eudoxia nectocalyces was, however, excellently 
preserved, and from these there can be no doubt that the form is 
identical with that described by Eschscholtz, although the serrations 
of the edges of the ridges are much less pronounced than in the examples 
figured by Huxley. The larvae of two species of Echinoderms 
occurred in moderate numbers, one being a Pluteus with broad flat 
arms, probable that of an Ophiuran, and resembling in general form 
that of Ophioglypha texturata figured by Mortensen,‘ the other a large 
Brachiolaria with a circular adoral ciliated band. Neither of these 
forms can at present be referred to their adults. 
A few examples of an unidentified Annelid larva were also ob- 
tained and a considerable number of Cyphonautes. 
Especially interesting were the Crustacea, inasmuch as they 
excelled both in number and variety all the other groups. Of the 
Cladocera, two species were present, Evadne nordmanni Lovén and 
Podon polyphemoides Leuck, less abundantly. 
Of Copepoda, by far the most abundant was Acartia longiremis 
Lilljeb., this constituting in bulk about one-third of the entire collec- 
tion. Much less frequent, although still in fair numbers, was a form 
that I identify as Centropages hamatus (Lilljeb.) Giesbrecht, although 
the armature of the genital segment of the female does not quite 
correspond with accounts of that form, several rows of short setæ 
occurring on the lateral portions of the dorsal surface of the segment, 
(fig. 1) in addition to the strong recurved ventral spine in front of the 
genital opening. The fifth thoracic feet in both sexes also depart 
slightly from described conditions, the internal projection of the second 
joint of the external ramus of the female being apparently longer 
than usual and denticulate (fig. 2), while in the male the terminal 
forceps of the right external ramus is somewhat longer and more 
curved and the spines of the left external ramus more reduced (fig. 3). 

1K. C. Schneider. Mittheilungen über Siphonophoren, III, Zool. Anzeiger, 
XXI, 1898. 
2E. Vanhôffen. Siphonophoren. Nordisches Plankton, 1906. 
3T. H. Huxley. Oceanic Hydrozoa. London. 
4Th. Mortensen. Nordisches Plankton IX. 
Sec. IV, Sig. 3 
