TARDIGRADA: CANADA 169 



that has a " comma " in the pharynx, and the egg is figured with the processes close 

 together at their bases, so that there is no room for the " areolation." 



There remains M. echinogenitus b, which, with the separation of a, becomes the 

 type of the species. It has the two bacilla equal, a not very common arrangement, 

 and the claws united at the base or for a short way above the base ; the surface of 

 the egg is not " areolate." A great many of the records of this species must be 

 regarded as doubtful. Many of these were made before the related species areolatiis 

 and harmsworthi were discriminated, so that unless details of the pharynx are given 

 it cannot be known to which form a record refers. It was till recently supposed that 

 the eggs of echinogenitus and harmsworthi could be distinguished. The original 

 specimens of the eggs of harmsworthi had processes much more shortly acuminate than 

 those of the typical echinogenitus, but some have recently been seen with points 

 almost as long. Records of echinogenitus have been commonly made (at any rate in 

 my papers) on the strength of finding the egg alone. Although the eggs with short 

 points may be usually harmsworthi and those with long points echinogenitus, there 

 will always be doubt about these records unless the eggs are so ripe as to show 

 pharynx and claws (see p. 89, footnote). 



M. polaris has the surface of the egg "areolate " in the same manner as in one 

 form of areolatus (Fig. 53e), and the processes may be of the same form. It is, 

 nevertheless, a totally different egg, being much smaller, and with the polygons 

 relatively much smaller, and therefore more numerous. 



Macrobiotus harmsivorthi, Murray (19) 



Habitat. Near the Lake of the Woods, and in the public parks, Ottawa. 



The identification was made from eggs which contained young in which the 

 pharynx and claws could be seen. The egg measured 60 /a. without the processes, 

 and 80 n over the processes. These were even shorter than in the type, being 

 considerably broader than long. The claws of a pair were unequal, and united for 

 about half the length of the larger one. 



A very similar egg, but of larger size, was got in Ottawa. It measured 80 /*, 

 without the spines, and 120 n over the spines. The pharynx and claws were 

 not seen. 



Macrobiotus occidentalis, sp. n. (Plate XXL Figs. 54a-54e) 



Specific characters. Large, orange-red ; stomach and eggs darker red ; skin 

 hyaline, dotted ; gullet narrow ; teeth moderately slender, curved ; pharynx shortly 

 oval, with apophyses and two rods, the second shorter, and no " comma." Claws of 

 hufelandi type, united half-way. Egg spherical, covered with slender tapering 

 curved processes, which are separated at their bases. 



General desertion. Total length up to 800 p, pharynx of small example, 



BRIT. ANTARCT. EXPED. 1907-9. VOL. I. 7, 



