peesident's address. 109 



the fragility of their structure often escape notice. Isopoda, 

 especially Apscudes, Tanais, Anthura, and allied genera, Amphi- 

 poda, Ostracoda, and Cirripedia, all seem to be represented at 

 the greatest depths. 



AifNELiDA. — The Eeport on the ' Challenger ' Annelida has not 

 yet been published, but twenty -nine species are known to inhabit 

 the North Atlantic in depths exceeding 1,000 fathoms. Thomson 

 tells us that an Annelid "allied to EupJirosyne'''' was procured by 

 the 'Challenger^ in 2,220 fathoms in the ISTorth Atlantic, and 

 that from a bottom of Ecd Clay, in the extreme depth of 2,975 

 fathoms, there came up "many long cases of a tube-building 

 Annelid, evidently formed out of gritty matter, which occurs, 

 though sparingly, in the clay. The tubes and their content were 

 found by Dr. Willemoes-Suhm to belong to the family Ammo- 

 charidse, closely allied to the Maldania or Clymenidse, all of 

 which build tubes of sand or mud." K'ear the Canaries the ano- 

 malous genus Balanoglossus was brought up from 2,500 fathoms, 

 where it was living on a dark volcanic sandy bottom. 



Gephteba. — The Norwegian North Atlantic Exploring Expe- 

 dition procured three genera of Gephyrea from depths exceeding 

 1,000 fathoms. A Gephyrea was dredged by the ' Challenger^ 

 on compact yellowish ooze in 1,945 fathoms near the Canaries, 

 which "Willemoes-Suhm regarded as " shewing a combination of 

 characters of the Sipunculacea and Priapulacea, " and to which 

 he gave the name Leioderma. 



Echlnodekmata. — Echinodermata of all orders are apparently 

 at home in all depths, and in the great abysses several groups 

 unknown in shallower parts of the ocean present themselves. I 

 have already referred to the Echinoid families, Saleniidae, Echi- 

 nothuriidse, and Ananchytidae ; and also to the Crinoidea. The 

 Sea Puddings are largely represented by an entirely new order, 

 Elasipoda of Theel, the numerous members of which are every- 

 where present in the abyss of the ocean, but very rarely appear — 

 if we except one or two forms in the Arctic Regions — in less than 

 500 fathoms. Asteroidea and Ophiuroidea abound; among the 

 former the new genus Hymenaster, which has numerous species, 

 is noteworthy on account of the delicacy of its structure. 



