98 



apex. Perichetial leaves nerveless, narrowed into an erect or 

 flexuous subulate point, entire or slightly denticulate. Capsule 

 cylindric-oblong, curved suberect or inclined, without a neck; 

 segments split their whole length or coherent at apex ; cilia rudi- 

 mentary ; annul us narrow; lid conic obtuse, depressed in the 

 middle and mamillate ; pedicel 1-1,5 cm. long, rough the whole 



length. 



H. Niittallii, Wils, but differs as above. On logs 

 and trunks at Nanaimo, Vancouver Island. June 8, 1887. Col- 

 lected by John Macoun. 



A Descriptive List of Staten Island Diatoms.* 



By E. a. Schultze. 



Plate XC. 



Navicula Carassius, Ehr. 



Navicnla Carassius, Kutz. Bacill. p. 95. t. XXVIII. fig. 67; Rabenh. Siissw. 

 Diat. p. 40, t. VI. 57; Ralfs in Piit. Inf. p. goo; Donkin Brit. Diats. p. 20, pi. 

 III. fig. 7; O'Meaia Rep. on Irish Diat. p. 412, pi. 34, fig. 20; Schum. Diat. der 

 Hohen Tatra, p. 68. 



Valve small, broadly lanceolate with produced capitate ex- 



Na 



tremities ; striae moniliform, reaching to the median line, conver- 

 gent opposite the central nodule and radiate towards the ends. 

 Hab. — Freshwater. Clifton. (Plate XC. fig. 13.) 

 A much smaller species than N. ptisilla with much finer 

 striae, and at once distinguished by its narrow produced apices. 

 Donkin. 



It is more than doubtful if the form described by Donkin as 

 viada Carassius belongs to this species. The figure repre- 

 sents the form as very much longer, the ends finer and more 

 produced, than is the case in Navicula Carassius ; the striae too, 

 are described as granular, the striae in Navicula Carassius are 

 linear. Donkin regards the species as identical with Navicula 

 lacustris, Gregory, A. J. M. S. 1856. p. 6, Pi. I. fig. 236, but the 

 true Navicula Carassius is broadly elliptical, and not linear as the 

 former is represented to be. — O'Meara. 



There is a noteworthy difference of opinion between O'Meara 

 and Donkin, as to the outline and stri^ of Navicula Carassius. 

 The Staten Island form closely resembles the figure drawn by 

 West in Donkin ;^ the form represented by O'Meara is almost too 

 small for comparison. 



*Coiuinued from Vol. XIV., p. 114. 



