25 
The Mysidacea are but little known from our waters, and much 
very important work requires to be done in collecting these Crustacea 
which have probably evaded the more general collecting apparatus 
used along this coast. Probably a light net — something between a 
dredge and a tow-net — used over the Zostera beds would result in 
their capture. 
Numbers of Anomura have been captured, and three of the 
four tribes making up this section are known to occur — The 
Galatheidea, Thalassinidea and Paguridea. What is probably the 
first record of the Thalassinidea is a fine specimen of Thalassina it- 
self, dredged in the mud of the Swan River right opposite Perth. 
Alpheids appear to be abundant down the coast, and the same 
may be said of the Sphaeromidae, a family of Isopods. A very near 
relative of the family, Limnoria sp., occurs in thousands in Fre- 
mantle Harbour, boring into the piles and preparing the surface for 
the attacks of the “shipworms.” It is a species of Limnoria which 
works similar havoc in many parts of the world far removed from 
Australia, is known popularly as the Gribble, and was first discovered 
as a British species by Robert Stevenson, the lighthouse engineer, 
who found it destroying the timber used in the erection of the Bell 
Rock Lighthouse. 
Echinodermata. — The Crinoids, Ophiuroids, Asteroidea and 
Echinoidea are tolerably well known from the region south of Sharks 
Bay, but a gap remains in our knowledge of the phylum, even in 
this region, owing to the absence of information on the Holothurians. 
Holothurians are quite common and several genera have been 
collected; in some places the sea bottom is particularly rich in these 
echinoderms. A collection will be sent away in due course for exam- 
ination by Dr. Pearson, of the Colombo Museum, Ceylon. 
The other groups are better known, owing to the work of the 
West Australian Museum and that of the Hamburg Expedition in 
collecting these forms. Thirty-one crinoids have been recorded from 
the West coast of Australia. Thirty-two Ophiuroids are known from 
the South-West region of our coast, and about eighteen species of 
Asteroidea. This latter number certainly does not represent all 
the species so far collected. Some large specimens of a species of 
Luidia more than a foot across have been dredged near Garden 
Island. It is very difficult to preserve them without breakage of 
the arms taking place.* 
Tunicata. — The phylum Tunieata is one of the dominant groups 
of marine animals on our coast, and the jetty piles at all the seaports 
are covered with these organisms. 
•Since re 'ding this address, the West Ans’ralian Museum have published a list of the 
Echinoderms in their collection. It is probable that the species recorded as Lmiia 
viucuLata M. & I., is Luidia maculnta. It is very probable that our large specimens 
belong to this species, which occurs at Ceylon, 
