ARCHER, ON CLOSTERIUM ACICULARE. 31 



find no little work ; and, as a sample of wliat we may meet 

 with in this class of objects, let the spicular liooks of the 

 Synapta (a very common slide), be examined by polarized 

 light, and the result will surely draw the observer on to 

 further researches. 



The scales of plants and ferns, with theii* usual star-like 

 forms, are already well known, but they are as yet far from 

 exhausted ; and some of the foreign specimens are still new 

 to most, if not all, of the microscopic world. 



I look upon polarized light as a country whose borders only 

 are yet known. If one inquiring mind is stirred to this study 

 by my few and incomplete remarks^ my object will be attained 

 in writina: them. 



On Closterium aciculare (West). 

 By W. Archer, Esq. 



In the ' Quarterly Journal of Microscopical Science,^ vol. 

 VIII, p. 153, Mr. Tuffen West described a new species of 

 Closterium under the above name, and, appended to his de- 

 scription, he did me the honour to quote a few lines of mine 

 to him in regard to it. I had then seen only a hurried 

 tracing, but had not seen either Mr. West's truthful figure 

 (1. c. PI. VII, fig. 16), or an actual specimen, and, if so, I 

 should perhaps have written slightly differently, while, 

 moreover, the printers have misplaced a stop, thus rendering 

 my meaning douljtful. Under these circumstances, I trust 

 I may be allowed a xery small space to point out the error 

 alluded to, and to try to make what I then meant to convey 

 more clear. 



By saying that the great length and slight breadth of the 

 form named Closterium aciculare by Mr. West, brought it 

 near to Closterium, praelonyum (Breb.), I merely intended to 

 state that, proportionate length and breadth being considered, 

 these two species were amongst the most slender in the 

 genus, and not that any more immediate affinity existed 

 between them. Since the occasion referred to, I have had, 

 by Mr. West's kindness, an opportunity to examine authentic 

 specimens of his C. aciculare, and lately I have had the 

 pleasure to meet both these species in Ireland (very sparingly 

 indeed, but they are each scarce, or '^Wery rare"*to the dig- 



