706 SCIENTIFIC RECORD FOR 1883. 



IV. CCELENTERATES. 



Polyps. 



A new type of Pcnnatuloid Polyps. — A remarkable form of Peuuatuloid 

 polyps has been recently discovered by Messrs. Koren and Danielssen 

 in a special work on New Alcyonids, Gorgonids, and Peunatulids of the 

 Norwegian fauna; it has been named Gonilul viirabilis, and specimens 

 were obtained in the fjord of Throndbeim at a depth of 180 fathoms, 

 attached to Oculina prolifera. This form represents a peculiar " sec- 

 tion " of Pennatulida, called " Gondulese," distinguished by the fixed 

 rachis with developed bilateral lobes, furnished with long calcareous spi- 

 cules. The Gondulidae were defined as Pennatulida Gondulese, having 

 " a polypidom without a stalk, fixed, furnished with bilateral pinnules in 

 which are calcareous spicules, having along its center a canal divided 

 by four valves into as many longitudinal canals." In other words, they 

 are Pennatulida Gondulese with a fixed, stalkless, bilateral polypidom, 

 having a rachis with a hollow canal divided by four converging longi- 

 tudinal septiform valves, and on each side with subspiral polypigerous 

 ridges, fortified by calcareous spicules. 



A deep-sea cancrisocial Actinian. — Several cases of association of 

 polyps with decapod crustaceans have been recorded (e. g., Cancrisocia 

 expansa with a Dorippe, Sagartia parasitica with an Eupagurus bernhar- 

 dus), but an instance recently discovered seems to be worthy of notice 

 in this place on account of the habitat of the associates and the extent 

 to which the association has been verified. The polyp has been de- 

 scribed as a new species by Professor Verrill under the name Epizoan- 

 thus pagurophilus, and about 400 specimens were obtained at one station 

 (947, 89 miles S. by S. £ W. from Gay Head, Mass.), at a depth of 312 

 fathoms, but all associated with a hermit crab, the Parapagurus pilo- 

 simanus. The polyp is evidently "a true commensal, forming out of its 

 own tissues the habitation of the crab; and hitherto it has not been 

 found elsewhere than upon the back of this particular species of crab, 

 which likewise has not been found without its polyp." The associates 

 were previously obtained "by the Gloucester halibut fishermen in 

 deep water, off Nova Scotia," and by Professor Verrill in 1880. (Am. 

 J. Sc. (3), vol. xxiii, p. 137.) 



Acalephs. 



Reappearance of Limnocodium. — It is noteworthy that the fresh- water 

 medusa, named Limnocodium Sowerbii, which appeared iu numbers in 

 June, 1880 and 1881, in the Victoria regia tank in London, did not de- 

 velop at all iu 1882. It made its reappearance, however, in 1883 in 

 the tank, but earlier than in the previous years, being discovered April 

 28. The tank had remained empty during the preceding winter, and 

 was filled with water on March 8. (-Nature, vol. xxym, p. 7.) 





