174 Transactions of the Royal Microscopical Society. 
amphioxys •which must be separated not only from the genus 
Nitzscliia, but probably from the family of Nitzschiese. 1 long ago 
proposed (in letters to various friends) a new genus (Hantzschia, 
in honour of Mr. Hantzscb and bis valuable researches on Nitzscliia) 
for their reception. 
The carinae of the valves of Hantzschia are not opposed 
diagonally, but are situated at the same side of the frustule which 
bears a great resemblance to those of Epithemia and Eunotia. 
The following are the species belonging to the genus Hantzschia : 
If. amphioxys 
II. vivax 
II. elonyata 
II. virgata 
II. marina 
Eunotia and Nitzscliia. 
Nitzscliia vivax. 
„ elongata. 
„ virgata. 
Epithemia marina. 
and a few other which are more or less dubious. 
Mastogloia. 
M. erythrsea Grun., ‘ Verh. Wien zool. hot. Gesellsch.,’ 1860, 
tab. vii., fig. 4 (mala). Common in the Honduras gathering, Eed 
and Adriatic seas. My former delineation of this diatom was not 
very correct, having been made from a small and badly cleaned 
specimen. I therefore give better in PI. CXCIV., Figs. 12, 13, 14. 
The loculi are very narrow (12 in • 10 mm.), and interrupted at two 
places by one, two, or three loculi of somewhat larger dimensions. 
The slightly radiating transverse lines are very fine, the longi- 
tudinal are coarser (12-14 in • 01 mm.) and undulating hke the 
median line. 
M. erythrsea var. hiocellata Grun. n. var. ? loculis mediis ceteris 
majoribus, striis distantioribus (24 in -01 mm.). Tab. CXCIV., 
Fig. 15. 
Very rare in the Honduras gathering. 
The enlargement of some of the loculi seems to be of little 
specific value ; I have seen a var. of M. quinquecostata where the 
large loculi are arranged in the same manner as in M. erythrsea. 
In some other species (M. apiculata and M. Braunii) only two or 
three loculi in the centre of the valve are occasionally enlarged. 
Mastogloia Jelineclcii Grun. (Grun. in ‘ Verh. Wien zool. hot. 
Gesellsch.,’ 1863, tab. v., fig. 12). Honduras, Brazil, Campeachv 
Bay, Virgin Island, West Indies, &c. This is a species of Masto- 
gloia with very small loculi resembling those of some varieties of 
M. quinquecostata. PI. CXCV., Fig. i. 
M. rostellata Grun. (M. Jelineclcii var. ? rostellata Grun. in 
Hedwigia). M. valvis oblongis medio minime constrictis, polis cuneato 
