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

368 COLLECTIONS FEOM MELANESIA.Chalinidae are especially abundant (16 species, 5 new). No essentiallynew types occur; but of two new genera, one (Toxochcdma)is formed in recognition of a character, hitherto overlooked, connectingthis family with the Desmacidinidae. Seventeen Kenieridse (5new) occur, which are chiefly remarkable for their close resemblanceto European forms, all the genera and three species being alreadyknown from Europe. The Desmacidinidoe have 19 species, andinclude 9 now forms, and a species for which I have established anew genus, Gelliodes, which appears to be an extreme developmentof the well-known European GelVius (Desmacodes, Schmidt), alsotwo species for which a genus (lotrochota) is formed, in tardyrecognition of their great distinctness ; it is probably related ratherto the deep-sea genera Chondrodadia and Cladorrhiza than to anylittoral genera, except Monanchora, Carter, and is remarkable asbeing a persistent littoral representative of what was probably oneof the earliest types of Desmacidines, viz. that in which the auchoratespicule was symmetrical. Such old types usually survive only inthe deep sea or fresh water ; we have already seen that the deep seaproduces examples of it, and probably the Spongillidte with birotulatespicules are also modern representatives of this type, which(or whose ancestors) have taken refuge in fresh water. Eemai'kableas are the outward forms assumed by the species of Rliizochalinahere described, they will not surprise those who have studiedthe paper in which Mr. Carter recently described (under the namePMceodictyon) a number of species belonging to this genus fromvarious parts of the world ;perhaps, however, Torres Straits willprove to be more prolific in this respect than any other locality.The Ectyonidae are remarkably rich in new forms (10 species outof 17). Cktthria, which is small in growth and not very rich inspecies even in the Mediterranean, here assumes a great developmentin size and number of species. The distribution of the Axinellidaeis as much bathybial as littoral, in accordance with whichfact we only have three species here. Of the 8 species of Suberitidae,4 are new.The suborder Tetractinellida is, in conformity with the fondnessfor greater depths and the relative scarcity of individuals which itsmembers commonly exhibit, represented by only 7 species, of whichfour are new, and all belong to the Choristidae (Sollas).The Calcarea are poorly represented (3 species), and afford nothingof great interest from a taxonomic point of view.I have given further details, where necessary, of the more remarkablesystematic points under the different groups themselves, and aclassified list of the species is inserted in the account of the GeographicalDistribution.Anatomy and Histolor/y of Soft Parts.—Want of time has preventedme from thoroughly investigating these subjects at present,interesting and important in the extreme as they are, and favourablein many cases for the purpose as is the material contained in thecollection. A few notes relating specially to the histology willbe found scattered throughout the <strong>Report</strong> (see especially Aplysina,