218 Zoological Society : — 



is forked at each end ; these branches grow and divide again, until 

 the plate is all sketched out, the margin being added last, and the 

 whole becoming more solid. We have not met with any figure of 

 the spicula of »S'. diyitata, except the bad one given by J. Miiller, 

 whose work we have only been able to see in the Library of the 

 Museum of Practical Geology. 



2. Synapta (Holothuria) in h^erens, O. F. Miiller. 



The second European Synupta was discovered at Christiansand, 

 on the coast of Norway, and figured and described in the ' Zoo- 

 logia Danica ' (1781). The anchors and plates are also figured 

 in the admirable Memoir of Duben and Koren*. The ana- 

 tomy of this species is described at some length by M. Quatre- 

 fages f , who regarded it as a new species, and called it S. Duverncea. 

 These specimens were obtained on the coast of Brittany, at the Isles 

 Chaussey near St. Malo, where they were very abundant in the mud 

 near low water, and attained a length of 10 to 18 inches, with a dia- 

 meter of 5 to 12 lines. 



The anchor-plates of this species more nearly resemble those of 

 the Red Sea S. vittata than the last. They are oval, \vith no arch 

 or process at the articular end ; and the disk is perforated by six 

 oval cells surrounding a central opening each with a scolloped border, 

 as in S. vittata. 



The anchors have serrated flukes, the serrations varying from 3 

 to 7 ; and the anchors are sometimes shorter than the plates, some- 

 times considerably longer. 



The miliary granules are few, and confined to the muscular bands ; 

 they are only half as long as in S. digitata, and rudely crescent- 



A. specimen of this Synaptu was obtained by Mr. Henslow at 

 Aberystwith, and communicated in 1819 to Dr. Leach, who labelled 

 it " Jemania Ilenslowana.''' It is a small individual with imper- 

 fectly developed spicula, but showing the characteristic pinnate ten- 

 tacles. 



In June 1856 Mr. J. W. Wilton, of Gloucester, found another 

 example at Criccieth, on the same coast of Cardigan Bay. It was 

 discovered under a stone, at low water, and presented the appear- 

 ance of " a clear pinkish waving worm, about 3 inches long, with a 

 number of little papillse all over it, and five faint longitudinal bands 

 from head to tail. It had twelve tentacles, with five digits on each 

 side. It was perpetually waving and swelling in one part, contract- 

 ing in another :j;. It lived but a short time, and finally constricted 

 itself and broke up into half a dozen fragments." 



In February 1856 Mr. E. C. Buckland obtained a finer specimen 

 under similar circumstances, in Lihou Bay, Guernsey. A micro- 

 scopic preparation of the skin of this specimen shows 150 anchors 



* Proceedings of the Royal Academy of Sciences, Stockholm, 1846. 

 t Annales des Sciences Nat. 2 ser. t. xvii. Zool. p. 19. 



+ I'orskal named one species Synapta reciprocans, on account of these remark- 

 able muscular movements. 



