NATURALISTS’ FIELD CLUB

Evening Star, Issue 17954, 27 April 1922, Page 2

NATURALISTS’ FIELD CLUB

‘ ANCESTORS OF THE OCTOPUS,’

The indoor meeting of the lucid Club held on Monday evening proved intensely interesting to the members. .Mr Williams, vice-president, was in the chair. Mr 11. Finlay read a- paper entitled ‘Some Ancestors of the Octopus,’ in which was traced the gradual rise of these, animals from their earliest known forms. The paper mentioned how in tho earliest fossil-bear-ing rocks inimistakablo evidence is found that tho shellfish were even then well developed, but that the only representatives of the arm-footed animals, tho class to which tho octopus belongs, were certain primitive straight-shelled forma allied to tho nautilus of tho present day. Those soon gave way to tho Ammonites, a curious class of shells whose members are now wholly extinct. They were at first a very actively growing race of great vital power and evolutionary susceptibility, but. probably through attempting too much, and exorcising their powers of change to excess, they exhausted tho race, as well as their individual selves, and .all finally perished. Tho paper then dealt with the rise of a new stock; the Belemnitos, or “ thunderbolt ” fossils, and tho various tranches that evolved from them; how these animals (which must have looked very much like cuttlefish, but had a much larger internal skeleton) tended to give up a sluggish life on the sea, floor and take to the open ocean. This necessitated greater activity and intelligence ; there was thou less need for tho protective shelly skeleton, which was thus gradually reduced, till most of our modern squids possess only the long thin “ ten.” One of tho descendants of these forms which hn.s retained a coiled and chambered shell is Spirnlu, whoso shell is cast up in thousand's on New Zealand shores, though tho animal is very rare indeed. The. paper dosed with an account of tho modifications of - the cuttlefish, structure that had led to tho rise and development of tho octopus • how tho ten arms had been reduced to eight, all of equal siae, together with changes of tho fins and loss of the internal shell The order to which tho octopus belongs is at its maximum at the present day, and contains tho highest number of backbonekss animals.

A lengthy and keen discussion followed, Mr Fin-lav being congratulated on the clear and lucid manner in which ho bad treated his subject. Two now members were elected, and a committee waa appointed to select a design for the- club badge. ‘Miss Cartwright brought forward specimens of fungi. Mies Scott exhibited a specimen of Rhyssa antipodnm and some beetles collected at Stewart Island. Owing to Saturday’s boisterous weather tho work of recording tho natural history of tho Otago Peninsula waa again interrupted, the excursion arranged for Tomahawk via tho Highcliff Rock being postponed. On May 6 tho chib will visit Fcmlnll and tho Silvemtream race, taking tho 1.15 p.m. train to Abbotsford.