ZZ Museum Notes

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Fig. 1. Pseudocalanus eclongatus Boeck (Copepod). Female carrying egg sac. X 80.

“2. Male of same species with characteristic sense organs on the basal portions
portions of antenae. X 80.

= 3. Nauphtus’ larvaco®same: x 20:

“4. “Nauplius” larva of a barnacle (Balanus balanoides). X 20.

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5. -«Cypris” larva of same species. Xi 20),

The Copepoda are an order of the Crustacea; they abound in both fresh water and
in the sea, forming one of the chief sources of food for many aquatic animals.
The eggs may be carried by the parent (Fig. 1) until they begin to hatch, or may
be deposited in the water; the young hatch out as nauplii (Fig. 3), which possess only
three pairs of appendages; these increase at successive moults until the adult forms

with six pairs of anterior appendages and four or five pairs of! legs is attained.

On the B. C. coast we have found the following species:

Calanus tonsus Euchacta norvegica

Calanus finmarchicus Metridia lucens

Centropages hamatus Scotlicithricella minor

Centropages memurricht Corycaeus venustus

Acartia claust Oithonia setigera

Acartia longiremus Oithonia similis

Pseudocalanus clongatus Oncaca subtilis

Microcalanus pusillus Microsetella rosea

Actidius armatus Paralavidocera amphitrites McMurrich

Tortanus discaudatus

Eight other species were collected in Puget Sound by Dr. Herdman in 1897, but
their presence in B. C. waters has yet to be ascertained.

All the above are of northern or Arctic habitat, except Wicrosctella rosea; this
species is numerous at the time of writing (December) in the vicinity of Nanaimo. It
has been recorded from La Jolla, California.

The above list is only a preliminary contribution to the marine Copepod fauna of
British Columbia.

Larval forms of barnacles are represented in Figs. 4 and 5; they belong to the
order Cirripedia of the Crustocea; the newly hatched young are similar to copepod
nauplii, but, after several moults, they develop a bivalve carapace; at this stage those that
belong to fixed forms attach themselves to some object by a sucker at the end of their
antennae and develop into adults, such as those that cover the rocks on our beaches in
such countless numbers.

The nauplii are found in large numbers in the ‘“‘plankton;” those in the cypris stage
are less numerous.

Eighteen species of sessile barnacles have been recorded from B. C.