2 Prof. H. James-Clark on the Affinities of 



towards the posterior end, which is thickened and rugose. 

 The anterior annulations are armed with two fascicles of 

 yellow bristles, of about three or four each, placed opposite to 

 each other : the rest of the rings have about two each ; but the 

 "numbers vary. Colour pale orange-red, the mouth with a 

 purple cast. Buccal cirri twenty, ten on each side of the oral 

 organ, white, beautifully maculated with oblong spots of 

 orange-red down the centre. Dorsal cirri reflexed, purple, 

 with a faint reddish tinge. 

 Length of the worm 2 inches, of the tube 3 inches ; diameter at 

 larger or anterior end 2 lines. 



This species constructs a rather flexuose tube made of a thin 

 horny substance similar to that of the polypidoms of the Sertu- 

 larias, and coated with grains of sand and comminuted shells, 

 with bits of corallines attached. 



The worm is able to raise its head considerably above the first 

 or anterior ring, bearing the dorsal cirri, as shown in the figure 

 (Plate I.) on the right. Generally speaking, its movements 

 were slow; but when fully protruded it is a beautiful creature, 

 the dorsal cirri contrast so strongly with the delicately painted 

 buccal organs. I kept it alive for several days, and I found 

 that it seldom protruded itself by day; but as evening closed in 

 it would then develope itself to its fullest extent. 



I am. Gentlemen, 



Yours obediently, 

 Edward Parfitt. 

 Devon and Exeter Institution, 

 April 21, 1866. 



II. — 071 the Affinities o/Peridinium Cypripedium, Jas-Clk., and 

 Urocentrum Turbo, Ehr. By Prof. H. James-Clark, A.B,, 

 B.S., Soc. Am. Acad. 



In the 'Proceedings of the American Academy' of February 

 1865 I published a paper on the anatomy and physiology of 

 Peridinium Cypripedium, mihi. That article, with the accom- 

 panying plate, was copied into the ' Annals and Magazine of 

 Natural History' for October 1865. In the December Number 

 of the same 'Annals' I find some remarks on my paper by 

 Mr. H. J. Carter, the principal aim of which is to show that the 

 animal which I have described is not a Peridinium but a Uro- 

 centrum. I wish, through the mec^um of your Magazine, to 

 give my reasons why I did not formerly, and do not now, believe 

 that the identification of that gentleman can be sustained. 



Let me state, in the first place, that the whole question hinges 

 on the identification of the animal as described and figured by 



