Report on the zoological collections made in the Indo-Pacific Ocean ...

:146 COLLECTIONS FROM MELANESIA.26. Euryale aspera, Laml:Lyvian, p. 43.(a) One specimen, Port MoUe, 12 fms. ; bottom, rock and sandof a dark black colour.(6) Several specimens. Port Curtis : all lighter in colour.HOLOTHUEOIDEA.A considerable number of specimens belonging to less than twentyspecies were collected, Colocliirus tuberculosus being extremely wellrepresented ; in the case of rarer or less well-known species, unfortunately,a single representative was often all that was obtained,so that in some cases conclusions have been arrived at which cannotbe regarded as any thing more than provisional. Where a numberof specimens were collected, or where the species was already representedin the British Museum, evidence was frequently obtained asto the wide extent of variation within the limits of ap])arent species; and this has especially made the work of discrimination ananxious and difficult one. Other difficulties were presented by theextreme density of the integument of some of the species and ourslight knowledge of tlie characters of the group. On the otherhand, the work of bibliographical research has been but slight, thethree more important workers at the group (Professors Semper,Selenka, and Ludwig*), having published works of remarkable exactnessand care.The arrangement followed is that of Prof. Semper.Semper, Hoi. p. 11.1. Synapta grisea.The condition of the single specimen did not admit of an anatomicalinvestigation, so that the characters of the calcareous ringwere not discovered; the form of the anchoring-plates is, however,exactly that of the species described by Semper under this name.That the species has a wide distribution would seem to be shownby its presence in this collection, and by its being represented by aspecimen from the Indian Ocean in the Loyden Museum f.Fitzroy Island, Queensland.Semper, Hoi. p. 47.2. Cucumaria maculata.From the external characters of the single specimen one wouldhardly be led to associate it with this species ; but in the case of* Dr. Tbeel's work does not seem to touch the present coUoctiou.t See Ludwig, Notes Leyd. Mus. iv. p. 128.