PLATE XXVII. 
Fifj. 1. Microscopic mineral particles from a Volcanic Mud, Station 262; 2875 fathoms, North Pacific. 
The particles are principally brown splinters of volcanic glass, showing in typical form the irregular 
outlines and conchoidal fracture, as well as the elongated fibrous structure of some varieties of 
pumice (magnified 175 diameters). 
Fig. 2. Mineral particles and fine washings of a Red Clay. Station 178; 2650 fathoms. South Pacific. The 
little colourless angular particles scattered over the figure are microscopic splinters of volcanic glass, 
or of minerals from eruptive rocks. Among these are vitreous fragments of a larger size as well as 
crj’stalline particles. The red-brown particles are palagonite. There are felspars and green par- 
ticles of augite (magnified 175 diameters). 
Fig. 3. Mineral particles of a Red Clay. Station 240 ; 2900 fathoms. North Pacific. These are essentially 
volcanic products. Among them may be recognised numerous fragments of pumice and other glassy 
volcanic particles, plagioclase, and palagonitic grains of a red colour (magnified 175 diameters). 
Fig. 4. Mineral particles of a Red Clay. Station 294; 2270 fathoms. South Pacific. As in the preceding 
figure, these are almost wholly composed of volcanic products, in which pumice fragments are the 
most abundant ; there are also felspar, plagioclase, green fragments of augite, red palagonitic par- 
ticles, and small crystals of quartz. The last are hexagonal prisms terminated by two pyramids ; 
two individuals at the top of the figure are united together with their vertical axes parallel. The 
brown-black particles are peroxide of manganese (magnified 175 diameters). 
Fig. 5. Fine washings of a Radiolarian Ooze. Station 225; 4475 fathoms. Western Pacific. This figure 
represents the exceedingly fine grains or flocculent matter, mixed with particles of volcanic glass, 
felspars, palagonitic and manganese grains, together with minute fragments of Radiolarians and 
other siliceous organisms (magnified 175 diameters). 
Fig. 6. Mineral particles of a Green !Mud. Station 189 ; 28 fathoms, Arafura Sea. This figure shows the 
difference in a mineralogical composition and in the dimensions and form of the grains in a terri- 
genous deposit compared with pelagic deposits, which are represented in the five preceding figures 
on this plate. Rounded fragments of quartz, sometimes covered with a reddish deposit of limonite, 
are the most numerous. Some colourless particles terminated by cleavages are felspar ; the rounded 
green grains are glauconite. There are also crystals of tourmaline and zircon (magnified 37 dia- 
meters). 
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