354 Mr Arnott's Description of 



which, in that genus, are pkced at the anterior part of the 

 sliell, and are sessile, while, in the fossil specimen, they are 

 placed on peduncles, though probably very short. The form of 

 the body approaches nearest to that of Cyclops^ but in this 

 genus there is but a single eye. 



We may therefore consider it as forming a new genus, which 

 may be called EidotJiea. 



The specimen was found in a limestone quarry at Bathgate, 

 where it attracted the attention of the workmen, from the 

 resemblance which they fancied it to possess to a human head ; 

 and it was obtained from them by Mrs Watson, of this town^ 

 who presented it to our Museum. 



With the exception of the TrilohiteSi I am not aware that any 

 crustaceous animals have been found in the mountain limestone ; 

 and although I have not visited that part of the country, yet, as 

 it is situated in the vicinity of coal-fields, I think there can be 

 no mistake in thus fixing on the geological position of this 

 specimen. 



Glasgow, May, 1831. 



Art. V. — On some New Species of Portulacece, By G. A. 

 Walker Arnott, Esq. A.M. F.L.S. and R.S.E. &c. 



The following plants I have received from Dr Gillies, along 

 with the Loasece described in the last number of this Journal. 

 They do not constitute the whole of the Portulacece discovered 

 by him, of some of which I have not yet obtained specimens 

 from him, although they have been already described in the 

 Botanical Magazine, and other works. 



Trianthema. 



T. americana. — Caulo herbaceo diffuso, ramis teriti-compres- 

 sis, foliis lineari-spathulatis, floribus brevi pedunculatis solitariis 

 polyandris trigynis. 



T. americana. Gill. mss. 



Hab. Near Laguna del Arbolito on the west side of llio del 

 Saladillo, forming the western limit of the Pampas. (November 

 to March, 1821.) 



This may ultimately prove to be a variety of T. polyandra 

 Blum, which, however, I only know by the specific character 

 given in De Candolle's Prodromus. The branches are, however, 

 there said to be terete, and the flowers (I presume longitudi- 

 nally) pedicellate. 



Tali NUM. 

 T. polygaloides. — Caule fruticoso erecto subramoso, raniis 

 striatis angulatis, foliis planis linearibus mucronatis, (siccitate 



