Boijal Microscopical Society. 9 



specific characters : — N. Perrijana, n, sp. mihi. Valve with deep 

 central constriction, dividing the valve into two ovato-cuneate por- 

 tions, margin composed of small monoliform granules, markings 

 composed of parallel costae not reaching median line or margin; 

 Callao. 



A curious variety of Stauroneis pulcliella is also of frequent 

 occurrence ; it has the outline and characteristic markings of 

 that species, but the so-called stauros is wanting. The strife are 

 nearly of equal length throughout the valve, leaving a lanceolate 

 smooth space, the margins of which coincide with the outline of the 

 valve. 



In a gathering from Islay, Peru, a few valves of Aulacodiscus 

 Kittoni, with seven and eight processes, have been found. 



