330 MK. G. MUEEAT AND MISS F. G. WHITTING ON 



DINOPHYSE^E. 



Phalaceoma, stein. 



'Fhalacroma operculatum^ Stein, and P. doryphoriun, Stein, occur pretty constantly 

 over the wkole region examined. P. Mitra, Schiitt, not so abundant as these, occurs, 

 however, over the region from the Azores to Panama. On PI. XXXI. fig. 7 we have 

 represented this species, since we are not satisfied with the author's presentment of some 

 of its details in his ' Peridiniacese,' pi. 4. fig. 18. P. Jourdani, Schiitt, occurred in one 

 gathering in lat. IT 58' N., long. 53" 32' W. P. porodictijum. Stein, also occurred in 

 one collection, viz. in lat. ZT 44' N., long. 30" 55' W. P. Globulus, Schiitt, occurs 

 from lat. 35° N. to lat. 20° IS"., and P. cunens, Schiitt, was found once only in lat. 24° 9' N., 

 long. 52° 50' W. Besides these we found four new species. 



P. Blackimaki, sp. n. Body divided into two unequal limbs by the girdle, nearly ovate, 

 covered all over (including girdle) with large, well-marked, 4-5-sided areolae ; girdle 

 projecting at both margins as a fine membrane with a row of acute tooth-like 

 supports ; proximal limb the larger, composed of two plates, with sail decurrent 

 nearly its whole length, supported by three short spines ; plates joined by a serrate 

 suture running lengthwise round the body and corresponding with a similar suture 

 on the distal limb, which also consists of only two plates and is slightly arched. 

 (PL XXXI. figs. 4«, b). 

 This l)eautiful JPhalac7'oma is by no means common, but occurred often enough to 



enable us to trace its distribution from the Azores to Panama. 



P. HiNDMAHCHii, sp. n. Body divided into two unequal limbs by the girdle, nearly 

 globular, with a protrusion at proximal end, uniformly marked with minute 

 spherical pits ; proximal limb the larger, with sail supported by three spines, the 

 lowest having a round knob at the end ; distal limb highly arched. (PI. XXXI. 

 fig. 5.) 

 Its distribution is from lat. 34° N. to lat. 14° N. It is closely allied to P. opercwlatum, 



differing from it principally in the singular protrusion from the proximal limb and in 



the character of the sail. 



P. DOLICHOPTERYGIUM, sp. n. Body very unequally divided by the girdle, and uniformly 

 covered with minute spherical pits ; girdle with its margins projecting as a fine 

 membrane supported by a row of spines ; proximal limb with sail decurrent its 

 whole length, narrower and projecting laterally on the side bearing the sail ; distal 

 liml) very slightly arched. (PI. XXXI. fig. 8 a, b.) 

 This species occurs from lat. 8° 51' N. to lat. 35' N. It resembles most nearly 



P. Mitra, from which it may be distinguished by its shape, long decurrent sail, and 



finer markings. 



