136 The Ottawa Naturalist. Jan. 



alive in their box. Within a very short time I always noticed 

 such flies either glued to the side of the box or the glass-lid, or 

 creeping slowly with wings or legs glued together. On touching 

 Peripatus it usually shoots out a delicate spray of gummy ma- 

 terial from two apertures on the pair of oral papillae under the 

 head. This gum or slime is so tenacious that it is difficult to 

 remove from the hand, and one of its uses is to capture active 

 prey like flies, etc. 



Why is it that Peripatus is of such surpassing interest that 

 Professor Moselev declared it to be an animal of great antiquity 

 and my friend Dr. Shipley, Master of Christ's College, Cam- 

 bridge, pronotmced it "one of the most interesting animals 

 known," from a morphologist's standpoint? 



Its distribtition indicates its ancientness. It is nowhere 

 very abundant, but it occurs in New Zealand, Australia, the 

 Cape, South America, St. Thomas and the West Indies, Panama 

 and possibly Sumatra. To the naturalist such a sparse but 

 widespread distribution means that it is a dying type, once 

 abttndant and of former wide occurrence. But it is a stem form, 

 or connecting link, and just the kind of animal so rare, and yet 

 so eagerly looked for bv the evolutionist. It seems to be the 

 very form from which the two vast animal Phyla, the Annulata 

 and the Tracheata, have sprung. Nay, even the Echinodermata 

 and the Mollusca seem to have features which they may have 

 derived from Peripatus ; and forms like the ancient Crinoids and 

 the Xiphosuran, Limulus, or King-crab, though so ancient, 

 possess features less ancient and more specialized than Peripatus. 

 Its archaic generalized feattires are so many and so striking that 

 it is impossible to treat them adequately in this brief note. To 

 refer only to two salient points, it may be mentioned that the 

 Echinoderms, though radiate, have essentially a right and 

 left half in the form of the body; and in larval stages the sym- 

 metry of the body is most strikingly bilateral: but this is dis- 

 gtiised later by the radial arrangement of parts. In the King- 

 crab the compound eye is not a primitive feature, and the pres- 

 ence of internal skeletal elements (endosternite) a complete 

 capillary system in the blood-vascular arrangements, the 

 specialized nephridium, or kidney, in the shape of the coxal 

 gland with attached lobes, and the massed nervous system 

 (brain, oesophageal collar and reduced ventral cord) are all far 

 less primitive than the annulate Peripatus. Indeed as one 

 facetious observer says, Limulus must be later than the Annu- 

 lates, for it fed upon them, the food of the King-crab being 

 various marine annelids. Peripatus is an annulate in many 

 features, being like a chaetopod or worm in its cylindrical, 

 bilaterally symmetrical, body, its anterior nerve ring and pair of 



