o/" Pol jparium ambulans, Korotneff. 275 



as the condition might be designated with reference to analo- 

 gous phenomena among the sponges, to be ascribed? 



Now we might assume that such an astomatous condition 

 was produced in the very earliest period of larval life, so that, 

 there being no formation of an oesophagus and corresponding- 

 central gastral space, the first-formed septa grew towards one 

 another and became united ; but in this way there would 

 result a series of partitions forming transverse chambers, and 

 continually increasing in number ; the place for the mouth, 

 which never became formed, would upon this supposition be 

 no doubt localized upon the upper surface and in the median 

 line of the band-like body. 



Such an assumption, however, is opposed by a structure in 

 the body oiPolyparium which rather indicates a different inter- 

 pretation and other processes. This is the figure of the poly- 

 pary, which is certainly described, but not further specially 

 applied, by Korotneff. For while the transverse chambering 

 of the band-like body produced by polyp-septa appears an ex- 

 ceedingly abnormal structure, it becomes still more remark- 

 able from the fact that the two long lateral margins of the 

 body are so differently constructed that they cannot well be 

 referred to the uniform periphery of an Actinia or Coral 

 extended longitudinally. And these differences between a 

 rounded-off and a bordered longitudinal margin are so far 

 continued upon the upper surface which bears the " buccal 

 cones," that the latter on the last-mentioned margin are 

 placed close together like palissades, while they stand sepa- 

 rately near the other margin. This asymmetry of Polypa- 

 rium seems to me to furnish an indication of the derivation of 

 this singular animal form. 



I imagine from this that this astomatous polyp was pro- 

 duced in this way — a typically constructed Actinid with a 

 central mouth and complete circlet of tentacles underwent at 

 some time, and in a manner still to be elucidated, a division 

 by which a portion of the body of the polyp was separated at 

 the lateral margin of the mouth-aperture ; perhaps the pro- 

 cess took place in a form in which a long, fissure-like mouth 

 was situated between the two directional chambers, and 

 parallel to its long diameter. If then, after such a process of 

 division, a union of the margins of the wounded surface took 

 place, this would produce the form of a polyp without any 

 central gastral space, with an internal cavity transversely 

 chambered by septa, and at the same time with two dissimilar 

 margins, one of which was originally adoral, the other aboral 

 and a segment of the original wall. That margin of Poly- 

 parium on which the tentacles (" buccal cones ") stand in 

 close proximity would probably be equivalent to the latter. 



