380 Rev. T. A. Marshall on new Genera Australian Hydroid, of which, however, he possessed specimens of only the dried periderm. It would seem to offer one of the connect-ing forms by which the Campanularian pass into the Sertularian Hydroids through Coppinia, Reticularia, and Grammaria ; but, in the absence of all knowledge of the living animal, it is impossible to speak with decision as to its affinities. Lineolaria spinulosa, Hincks. XXXVI. — Descriptions of new Genera and Species ofEumolpidae from the Collection of the Rev. Hamlet Clark. By the Rev. T. A. Marshall. The time has not yet arrived when a satisfactory arrangement of this interesting yet difficult group can be hoped for by ento-mologists. The literature of the subject is in so confused and imperfect a state, and the undescribed forms are so numerous, that the materials for generalization are yet wanting, and much time must elapse before a sufficient groundwork for the system-atist can be established. The existing materials require to be thoroughly sifted, and several hundreds of undescribed species to be defined, before the work of oi-ganization can begin. To the former of these tasks, with a view to attempting the two latter, the present writer has been led to direct his attention ; he is therefore enabled to speak with some certainty of the na-ture of the difficulties to be encountered. With respect to the hitherto published genera and species, it is perhaps not too much to say that one-half ai-e insufficiently characterized, and rather impede than facilitate future labours. The writers in whose widely scattered works these descriptions are to be found vary much, as may be supposed, in their style and accuracy : a few only have performed their task in a perspicuous and permanent manner. Foremost among these is Mr. Baly, whose labours in this department are beyond all praise for minute accuracy and clearness. The descriptions of Prof. Boheman, of Blanchard, Germar, Thomson, Say, Lucas, Gerstacker, Leconte, and a few others are easy of verification. It is to be regretted that most of the other authors whose names are attached to described species have contented themselves for the most part with a brief and insufficient diagnosis, and often a mere indication. A few only of the genera can be regarded as permanently established : even the well-known Colaspis, as at present defined, will not exclude a number of forms obviously distinct. The uncharac-terized genera of Dejean's Catalogue embrace for the most part apparently natural groups, or at least they may be made to do so by a system of judicious exclusion. We will therefore first direct our attention to them, from a conviction that the conver-
BioStor
