NEW PERIDINIACE.E FKOM THE ATLANTIC. 327 



girdle, widely bifurcate, the bifurcations each terminating in an acute spine, with a 

 few^ minute projections round the foramen ; distal liml) bluntly conical, partially 

 areolate. (PI. XXIX. figs. 2 a, h.) 

 It occurs in latitudes between 20" and 10° ^". and longitudes 30° to 50' W. 



Peridinium Milneri, sp. n. Body unequally divided at the girdle ; girdle areolate, 

 with very oblique ends; proximal limb composed of mostly 4-sided plates, with 

 broad, clear, unmarked margins, the areolae being of irregular shape and size 

 and strongly marked, with projections at the extremity ; distal limb lid-like, 

 irregularly areolate. (PL XXIX. figs. 3 «, b.) 

 It occurs in lat. 29° to 31° N., long, 42° to 44^ W. 



P. Tripos, sp. n. Body widest at the girdle ; girdle composed of a single row of large 

 areola?, ends oblique ; proximal limb marked with rows of large areolae, with three 

 short acute spines at the extremity, foraminal area elongate ; distal limb the smaller, 

 areolate, with three short projections at the apex. (PI. XXX. figs. 4 a, b.) 

 It occurs in latitudes from 31° to 14 N. and longitudes 38" to 58° W. 



P. DoMA, sp. n. Body widest at the girdle ; girdle broader at one end, with 2-3 rows of 

 areolae, ends oblique ; proximal limb composed of large plates irregularly arranged 

 and areolate, foraminal area elongate, furrowed ; distal limb dome-shaped, areolate, 

 without distinct plate-structure. (PL XXX. fig. 3.) 

 It was obtained in lat. 34' to 39' N., long. 39° to 32' W. 



p. VEXANS, sp. n. Body widest at the girdle, without apparent plate-structure, pitted all 

 over, including girdle; ends of girdle oblique; proximal limb with two small 

 projections near the extremity of the elongate foraminal area ; distal limb bluntly 

 conical. (PL XXIX. figs. 7 a, b.) 

 P. vexans was found in lat. 44° to 47° N., long. 19° to 13' W. 



P. trirostre, sp. n. Body divided into two nearly equal limbs by the girdle, covered 

 with large areolae varying in size and form ; girdle wdth one row of large areolae 

 bordered by two smaller rows, ends wddely oblique ; proximal limb trif urcate, 

 foraminal area with unmarked projecting membrane ; distal limb bluntly conical. 

 (PL XXIX. fig. 5.) ' 



It was found once only in lat. 25° 41' X. and long. 49^ 31' AV. 



P. Blackmani, sp. n. Body equally divided at the girdle ; girdle finely areolate, 

 foraminal area in deep narrow furrows ; proximal limb widely bifurcate at the 

 extremity, with large four-sided plates l)ordering the girdle, clear and transparent, 

 but marked with exceedingly delicate areolae, beyond these plates the limb covered 

 with strongly-marked oval areolae to the ends of the bifurcations ; distal limb 

 conical, with clear plates bordering the girdle as in proximal limb, and beyond them 

 strongly areolate to the apex. (PL XXIX. figs. {) n, h, c.) 

 This very large and handsome Peridinium is of rare occurrence, but we record it from 



