902 Transactions of the Society. 



P. radiatus Bail., Smiths. Contrib., 1853, p. 6, fig. 13. 



Subcircular to elliptical, major axis 0*0525 to O'l mm., from 

 II to \-^Q times minor. Surface almost flat, rising but slightly 

 towards the processes. Colour pale grey. Central area rounded or 

 irref nlarlv elliptical, with long axis at right angles to line of processes, 

 indistinct,' from 0*0075 to 0' 0125 mm. broad. Markings irregular, 

 and granular on central area, outside of this areolate, minute, gradually 

 incrciising in size towards the border; row's converging around the 

 processes distinct, elsewhere straight or slightly convex towards the 

 processes, and radial. Border distinct, with evident radial strife. 

 Processes 2, subcircular, from 0"01 to 0*015 mm. broad. — A. Baileyi 

 Grev., Trans. Mic. Soc. Lond,, 1863, p. 41). 



The border is more evident in some smaller subcircular, than in 

 larger elliptical specimens from Nottingham U.S. 



Habitat : Nottingham deposit (Hardman !) ; Long Island, United 

 States (Bailey!*) ; New York Harbour (Kitton!*) ; mud from New 

 York Harbour ; mud from Hudson Paver at West Point (Bailey, 

 Weissflog !) ; Bockaway, Long Island, I'nited States (Bailey) ; 

 Pensacola (Grove !) ; Yera Cruz and Pensacola Bay (Deby !). 



P. Behji Leud.-Fort., Diat. Ceyl., p. 64, pi. viii. fig. 75. 



Circular, diam. 0*125 mm. Surface sloping gently between the 

 processes to the border. Markings rounded, granular, about 4 in * 01 

 mm. ; rows straight, radial, secondary indistinct concentric rows most 

 evident towards the centre ; interspaces hyaline ; indistinct short 

 radiating lines around the border, extending from about outer 2/5 of 

 radius, striae converging to the processes distant, short, straight or 

 slightly curved; apiculi round, widely placed, irregular, forming a 

 single band near the border. Processes 3, irregularly elliptical or 

 more rounded, about 0*01 mm. broad. 



Habitat : Ceylon (Leuduger-Fortmorel). 



P. i^eruvianus. — Auliscus peruvianus Grev., Trans. Mic. Soc. Lond., 

 1862, p. 25, pL ii. fig. 6. 



Subcircular, elliptical or obtusely triangular, diam. 0*055 to 0*21 

 mm., major axis sometimes If times minor. Surface flat at centre, 

 sloping gently to the border, and rising gradually to the processes. 

 Colour pale grey. Markings polygonal, 5 in 0*01 mm., irregular at 

 the centre, elsewhere in straight radial fasciculate rows, those con- 

 verging to the processes almost straight in their central, but sharply 

 curved in their outer portion ; apiculi sometimes present, but incon- 

 spicuous. Border distinct, from 1/20 to 1/40 of radius broad, striae 

 10 to 12 in 0*01 mm., and at subregular intervals more evident 

 radial lines. Processes 2, rarely 1, 3, or 4, elliptical, in small valves 



• In the Collection of Dr. E. K. Greville. 



