186 NOTES ON A KECENT DKEDGING TRIP IN THE DEKWENT. 



obtained by me in the Derwent, three or four were most 

 certainly males. Since receiving Professor Hutton's letter I 

 find, on referring to Mr. Thos. Bell's able work, entitled " A 

 History of the British Stalk- Eyed Crustacea," the following 

 remarks respecting this particular Crab :—-" The species of 

 this genus are very remarkable from the peculiarity of their 

 being indebted to animals of a very different class lor 

 protection, although not truly parasitic. They are found 

 always to inhabit the shells of the Bivalve Mollusca, 

 pmerpally of the Genera Mytilus, Modiolus, and Pinna, and 

 occasionally also of the Ostrea, Cardium, and other Genera. 

 The^ males are always very much smaller than the females." 

 Bell's remark as to the scarcity of males agrees with what 

 came under my notice during the recent dredging trip. He 

 further states :■ — " This species, P. pisium, is very commonly 

 found in the common Mussel, Mytilus Edulis, on many parts of 

 our coast, and especially in those which are found in rather 

 deep water. On one occasion I dredged great numbers of 

 these Mollusca on the coast of Dorset, and found by far the 

 greater number of them with one or two of these little soft 

 bodied Crabs within their shells ; for the females are much 

 more_ common than the males. The latter sex I have 

 occasionally taken apart from the Mussel shells, the former 

 never." 



A large number of species of a delicate Echini were met 

 with, Echinocardium Australe, Gray, described by Gray in 

 1851. This species is found to have a very wide range, 

 having been obtained in the N.E. and North Coast of 

 Australia, Japan, S.E. Coasts of New Guinea, East Indies, 

 Cape of Good Hope, New Zealand, and New Caledonia. 

 The first specimens obtained in Tasmania were collected by 

 Mr. Bonald Gunn in 1850, and referred to by Gray in the 

 " Annals and Magazines of Natural History," 2nd series, vol. 

 vii., 1851. Two species of Hclothuroidea were obtained, one 

 species, Oucumaria, having five rows of ambulacral feet, the 

 other species, probably a Psolus, having only three rows of 

 tube feet on a kind of foot, like that of some Mollusca. I 

 forwarded some specimens of Cucumaria and Psolus to Mr. 

 Whitelegge, of the Sydney Museum, who is unable to 

 identify them with any species found in the Australian seas, 

 and is of opinion that they may be new species. Several 

 interesting specimens of Hydroid Zoophytes were obtained, 

 chiefly of the following species : — Sertularella divaricata, Busk; 

 var. sub-dichotoma, Bale. 



P. L. S., N.S.W., vol. iii. n.s., page 761. S. microgonia, 

 Lendenfeld. Bale, P. L. S., N.S.W., vol. iii. pt. 2., s.s. p. 763, 

 pi. xvi., fig. 8. Halicornopsis avicularis, Kirch. Bale, Cal. 

 Hydroida, p. 185, pi. x., fig. 1-2. Aglaophenia divaricata, 

 Busk. Bale, 1. c. p. 162., pi. xv., fig. 7-8., pi. xvii., fig. 6-7. 

 Several species of Polyzoa were brought up, the follow- 



