132 Dr. G. H. Fowler. [June 16, 



albumoses are precipitated by NaCl from their, in some cases neutral, 

 in others faintly acid, solutions. 



Besides the proteid we have found three undetermined substances 

 in the extracts, neither of which is proteid. The first of these (1) is 

 the substance which is present in considerable quantity in the watery 

 extract, and which is precipitated on adding a small amount of salt. 



(2.) When a portion of the first extract is freed from proteid by boil- 

 ing, and then the filtrate poured into alcohol, a precipitate is formed, 

 fairly copious but much less than that formed when the unboiled 

 extract is similarly neutral, as described above. This remains soluble 

 in water after prolonged action of the alcohol, but the solution gives 

 no xanthoproteic reaction. 



(3.) When the alcohol is evaporated to dryness a sticky residue is 

 left, which also is soluble in water, and its solution gives a fair xantho- 

 proteic reaction. This is not proteid, however, as it is soluble in 

 alcohol. This substance can be extracted from the fresh extract by 

 dialysing it in distilled water. On concentrating this dialysate a 

 similar sticky residue is obtained. In several cases this brown, sticky 

 Miass deposited crystals of rounded form, much resembling in appear- 

 ance the well-known aggregations of leucin. They were not leucin, 

 however, as besides being soluble in cold alcohol they did not give 

 the characteristic Scherer's reaction, nor did they form a compound 

 with the acetates of lead or zinc. It is not improbable that this 

 third undetermined substance may be allied to leucin, asparagin, 

 &c., but our observations on it are as yet incomplete. 



XI. " Note on the Structure of Rhabdopleura." By G. HERBERT 

 FOWLER, B.A., Ph.D., Assistant in the Zoological Labora- 

 tory of University College, London. Communicated by 

 Prof. W. F. R. WELDON, F.R.S. Received June 13, 1892. 



The specimens investigated were attached to a colony of Lophnhelia, 

 obtained by the " Challenger " Expedition at Nightingale Island, 

 from, a depth of 100 150 fathoms. I owe to Mr. John Murray my 

 thanks for his courtesy in allowing me to publish my notes on the 

 structure of this interesting form, in which I hoped that the improved 

 methods of microscopical research introduced in recent years might 

 re\eal points which had, perhaps, escaped the two observers to whose 

 fctndy of the living animal we owe our present knowledge of Ehabdo- 

 pleura. 



All the new anatomical features which I have been able to detect 

 are in entire agreement with the structure of C ephalo discus ; Rhabdo- 

 pleura may thus be taken to form a third member of Bateson's order, 

 the Hemichordata. They are, briefly, as follows : 



I 



