Genus Botryllus Gaertner and Pallas. Arnbäck-Christie-Linde and
Michaelsen in their recent papers recognise two
genera—Botryllus, forms with ovaries anterior or dorsal to the
testis and no incubatory pouch, and Botrylloides (synonymous
with Metrocarpa Arnbäck), forms with a single ovary with one
large egg on each side of the body situated posterior to the
testis and with an incubatory pouch present. In both genera the
anterior margin of the atrial orifice may be produced into a
long languet. For Synonymy and Literature see: 1922, Botryllus
leachi, Michaelsen, Vidensk. Medd. naturh. Foren., bd. 73, p.
479. This species forms soft, flat, irregularly-shaped masses on
the sides and under-surfaces of rocks between tide marks in all
three localities. Purple is the dominant pigment, but, as it
varies in depth and as varying amounts of yellow or white
pigment are present around the branchial apertures, a wide
colour range occurs. The test is grey, semi-transparent, and the
darker zooids and the terminal bulbs of vess