2o8 THE CANADIAN NATURALIST. [Sept. 



should have thought them iiuproperly used. I may add, that I 

 do not conceive how " a simple inspection " can decide on the 

 interpretation of facts, that can only be well understood through 

 inference from analogy. " Reasoning" is here indispensable, and 

 the only logical one is that which starts from a clear perception of 

 the morphology, evolution, and comparative anatomy of the 

 nearest recent representatives of the extinct types. 



As bearing highly on the present question, I shall lay before 

 the reader of the " Canadian Naturalist and Geologist " a tran- 

 slation of Professor Loven's description of his newly -discovered 

 recent remarkable representative of the palaeozoic Agelacrini and 

 Cystidea. 



"Professor Loven laid before the zoological section of the 

 Scandinavian Association of Naturalists, at Christiania, in 1868, 

 the figures of an Echinoderm hitherto unknown, viz., Hyponome 

 Sarsi, Loven,* and explained shortly its structure. Exteriorly 

 it resembles an Asterid, with five short and thick dicho- 

 tomously branching arms, but in other respects it differs 

 from all other recent Echiuoderms hitherto known ; while in its 

 most essential parts it agrees with the Cystidea, which were 

 hitherto regarded as extinct during the palaeozoic epoch. Among 

 these it most nearly approaches, through the want of a stem and 

 other characters, to Agelucrlnites (Vanuxem), and in other 

 respects to Glyptocystites (Billings.) As in Antedon and Penta- 

 crinus, a conical proboscis arises from one of the interradial areas 

 of the ventral surface. The ambulacral furrows, which distally 

 branch dichotomously, ulso give ofi" short branches to several small 

 club-like swellings of the perisome. These parts of the furrows 

 (the distal extremities and the branches) are open ; hut m the 

 ventral disk itself, in the vicinity of the point where they meet, 

 the limiting plates are seen to unite so densely from hath sides as 

 to form a vault, converting the furrows into covered-tip galleries, 

 which open into the visceral cavity through a common orifice, 

 situated near the centre, hut invisihle exteriorly. Small heaps of 

 microscopical Crustacea and other marine animalculae found in 

 these galleries, intimate that the food is picked up in the open 

 parts of the furrows, and, through these means, conveyed to the 

 hidden mouth. The covering of the ventral surface consists of 



* At the risk of some slight repetition we give both Dr. Loven and 

 Dr. Lutken's description of this interesting addition to our knowledge 

 of the Echinodermata. 



