162 



M.? dubia Cl. N. Sp. — V. broadly lanceolate, with cuneate ends. B. 0,07; B. 0,o3 mm. 

 Median line straight. No axial area. Central area small, orbicular. Along the median line is a 

 row of elongated puncta. Strise 16 in 0,oi mm. composed of distant, elongated puncta, forming 

 undulating, longitudinal rows, about 12 in 0,oi mm. Loculi not seen. — PI. II f. 38. 

 Marine: Barbados, foss. ! 



This form, of which I have found one specimen only, is perhaps a Navicula, but if so I 

 know of no allied form, nor am I acquainted with any kindred species of Mastogloia. 



M. egregia A. S. (1893) — a form of the group of M. lemniscata. — Atl. CLXXXVI f. 16. 

 M. electa A. S. (1893). — V. lanceolate, subapiculate. L. 0,056; B. 0,022 mm. Axial area 

 narrow, but distinct. Transverse striae 12 in 0,oi mm., slightly radiate throughout, composed of 

 puncta, arranged in obliquely decussating rows. Loculi 3 in 0,oi mm. of equal size, quadrate, 

 forming a band extending to the extremities. — Atl. CLXXXVII f. 3. Seems to be akin to 

 M. rostellata and M. asperula. 



Marine: Sandwich Islands (Atl.). 



M. Foliolum Brun (1893). — The figure is insufficient for description. — A. S. Atl. 

 CLXXXVII f. 45. 



M. funafutensis A. S. (1893). — V. lanceolate, apiculate. L. 0,046; B. 0,oi8 mm. Median 

 line straight. No areas and no furrows. Strise 9 in 0,oi mm. almost parallel, of coarse equi- 

 distant puncta, 9 in 0,oi mm. Loculi 7 in 0,oi mm. rectangular, forming a marginal band, ex- 

 tending to the extremities. — Atl. CLXXXVII f. 13. Characteristic species. 

 Marine: Eunafuti (Atl.). 



M. Griindleri A. S. (1893). — V. rhomboid-lanceolate. L. 0,045; B. 0,oi8 mm. Central 

 nodule unusually elongated. No areas. Strise 13 in 0,oi mm. transverse, composed of distinct 

 puncta. Loculi 5 in 0,oi mm., quadrate, in a marginal row reaching to the ends of the valve. — 

 Atl. CLXXXVIII f. 26. Seems to be akin to M. affinis. 

 Marine: Campeachy Bay! 



M. intersecta A. S. (1893) resembles M. erythrcea, but the fig. which shews longitudinal 

 lines, is too little detailed for description and identification. — Atl. CLXXXVI f. 38. 



M. (Orthoneis) latericia A. S. (1893). — V. broadly elliptical, with subrostrate ends. L. 0,07; 

 B. 0,04 mm. Median line straight. No areas. Transverse rows of alveoli 7 in 0,oi mm. slightly 

 radiate. Alveoli rectangular, arranged in obliquely decussating, curved rows. Loculi 4 in 0,oi 

 mm. rounded quadrate, of equal size, forming a marginal band, extending to the extremities. — 

 Atl. CLXXXVIII f. 40. A remarkable species, in some respects allied with M. asperula. 

 Marine: Kings Mill Island (Atl.). 



M. peracuta Janisch (1893). An apiculate form, apparently akin to M. Rhombus, but the 

 figure is too little detailed for identification — Atl. CLXXXVII f. 37. 



M. radians A. S. (1893). — Probably no Mastogloia, but a small form of Diploneis nitescens, 



at any rate too insufficiently figured to be admitted in to the system. — Atl. CLXXXVIII f. 28. 



M. remota A. S. (1893). — The figure is not sufficient for description. — Atl. CLXXXVIII f. 29. 



M. tumescens A. S. (1893). — This form is too imperfectly figured to be admitted into 



the system. — Atl. CLXXXVII f. 20. 



Stismaphora Wallich (1860). This genus, of which I have not seen any species, was founded by 

 Wallich (T. M. S. VIII p. 43). It seems to be akin to Mastogloia and comprises two pelagic species: 



1. S. rosirata Wallich (1860). — V. lanceolate, slightly gibbous in the middle, abruptly 

 constricted between the middle and the ends. L. 0,09 to 0,095; B. 0,oi4 to O.ois mm. Along the 

 median line is a row of equidistant puncta. Loculi 2 on each side, small, cuneate. — T. M. S. 

 VIII p. 43 PI. II f. 5, 6. — Pelagic: Indian Ocean (W.), Honduras (Grun.). 



2. S. lanceolata Wallich (1860). — V. lanceolate, acute. Median line without puncta, 

 otherwise as S. rostrata. — L. c. f. 7, 8. — Pelagic: Indian Ocean. 



