ON ARCTIC TARDIGRADA. 675 



M. zetlandicus, Murray (8). — This species, recently discovered in Shetland, was 

 abundant also in Spitsbergen. It is easily distinguished from all other known species 

 by the short thick rods in the pharynx, each deeply two-lobed on the outer side. 



M. annulatus, Murray (4). — Franz Josef Land, in two localities, and Bear Island. 

 Animals typical, but none seen carrying the egg-sac in the manner so characteristic of 

 the species. 



M. augusti, Murray ? (8). (Plate II. figs. 13a, 136.) — Previously known only from 

 Fort Augustus in Scotland. The identification is not quite certain, and depends on the 

 three narrow rods in the pharynx, the smooth eggs, and the form of the claws. The 

 middle rod is not decidedly shorter than the others, as in Scotch examples. 



Another example, with equally narrow rods and similar claws, had only two rods, 

 and thus resembles the newly hatched young, as found in Scotland. 



M. ornatus, Eichters (10). — Found only at Red Bay, Spitsbergen, where it was 

 abundant. Some skins with two eggs were found. 



M. tuberculatus, Plate (9). — Very insufficiently described by Plate, whose figure 

 and text are contradictory. . It is likely that there are several tubercled species besides 

 M. sattleri and M. papillifer, as I have found tubercled animals with different types 

 of pharynx. 



An example from Prince Charles Foreland agrees with Plate's description in having 

 very divergent claws. The tubercles are large and papillose ; there are four on each 

 chief segment and on each intermediate segment. The two pairs of claws are similar, 

 and one claw of each pair is longer. The pharynx is shortly oval, with three short rods, 

 increasing in size from first to third, besides a nut attached to the gullet. There are 

 two dark eyes. In size it is larger than other tubercled examples seen, measuring 300^ 

 in length. 



M. tetradactylus, Greeff ? (3). — An animal found in Prince Charles Foreland is 

 referred doubtfully to this species. 



Macrobiotus, sp. — In Franz Josef Land were found some examples of a species 

 which is common at the margins of Scottish lochs, and which is believed to be an 

 undescribed species. The claws are of the oberhauseri type, and the pharynx has two 

 equal short rods, a nut attached to the gullet, and a " comma." In Scotland the cells 

 forming the walls of the stomach are usually filled with blue granules. In specimens 

 preserved in spirit it is impossible to tell if the blue granules have been present. The 

 eggs are smooth, and are laid in the skin. See figure in " Tardigrada of the Scottish 

 Lochs" (4), Plate III. fig. 12, where it is erroneously named M. islandicus. At that 

 time the eggs had not been observed, or the error would have been avoided. An 

 example also occurred in Prince Charles Foreland. 



Macrobiotus, sp. — In Franz Josef Land there were found several examples of a 

 Macrobiotus which lays elliptical eggs in the cast skin. The eggs had been attacked 

 by a parasite, possibly a kind of Saprolegnia. From each egg there proceeded a tube 

 which penetrated the back of the skin of the parent and formed a slight expansion just 



