INDUSTRIAL PROGRESS DURING THE YEAR 1873. xciii 



generally iuhabits the latter, and so prevents the sponge 

 from encroachino' in this direction. Mr. H. J. Carter finds 

 {A?i7ials aiid 3Iag. of N^at. Hist., Jan.) that the flexible polyp, 

 ffydr actinia echinata, has the power of transforming the 

 calcareous shell on which it may be growing into its own 

 horn-like frame. 



Among tlie sponges' thus far obtained by the British ex- 

 ploring vessel Challenger, under Professor Wyville Thomson, 

 is a Venus' Flower-basket, or Euplectella, from off the coast 

 of Portugal, which it is impossible to distinguish from the 

 Euplectella aspergilluin of the Philippines. 



A valuable contribution to the subject of the develop- 

 ment of the coral polyp has been published by M.Lacaze-Du- 

 thiers in his new Archives de Zoologie experimentcde. He 

 confirms the statements of Dana that though polyps are true 

 radiates, still they have something of the antero-posterior (or 

 head-and-tail) polarity, Avith also the right and left, which is 

 eminently characteristic of the animal type. Still later he 

 has communicated to the French Academy further researches 

 on the coral polyps. He finds that the primary calcareous 

 particles are deposited in the internal layers of the walls of 

 the body, /. e., in the endoderm. He studied it on the coast of 

 Algeria; and in localities where, as he writes. Professor Car- 

 penter found nothing, he has discovered several new generic 

 types of corals. 



It appears that the late Professor Sars, from a posthumous 

 work on the animals of Norway, edited by his son, had de- 

 tected on the coast of N'orway a species of the coral Mopsea, 

 which he calls M. horecdis. Before this the genus was sup- 

 posed to be exclusively tropical, none having been found be- 

 fore north of the Mediterranean Sea and Florida. Another 

 coral, which occurs in the arctic fauna of the Gulf of Maine, 

 is the Deltocyathus Agassizii, which was found about twenty 

 miles east of Cape Cod by the United States Fish Commission. 

 It has heretofore been known to exist only in deep water off 

 Florida. A Fungia-like coral, named by Sars Fangiacythus 

 fragilis,\\Vi'& been found at great depths ofi"the coast of Nor- 

 way. It belongs to the free cup corals, of which there are 

 now few living representatives, and those confined to the 

 tropical seas. 



Amono; the discoveries of the United States Fish Commis- 



