Hi PROCEEDINGS OP THE GEOLOGICAL SOCIETY. 



me call your attention to the important conclusions which he draws 

 from the occurrence of this insectivorous mammal, to which he has 

 given the name of Spalacotherium t?ncuspidens, in the very same 

 formation in which such abundant remains of insect life had been 

 already found by Mr. Brodie and Mr. Willcox. "The chief interest,'* 

 says Prof. Owen, " in the discovery of the Spalacotherium is derived 

 from its demonstration of the existence of Mammalia about midway 

 between the older oolitic and the older tertiary periods," thus help- 

 ing to fill up that enormous hiatus between these two periods in 

 which mammalian remains had hitherto been found. He then alludes 

 to the interesting fact of these insectivorous animals being found in 

 such close neighbourhood to the insects themselves on which they 

 fed. He adds, " Amongst the numerous enemies of the insect class 

 ordained to maintain its due numerical relations, and organized to 

 pursue and secure its countless and diversified members in the air, in 

 the waters, on the earth and beneath its surface, bats, lizards, shrews, 

 and moles now carry on their petty warfare simultaneously, and in 

 warmer latitudes work together, or in the same localities, in their 

 allotted task. No surprise need therefore be felt at the discovery 

 that mammals and lizards cooperated simultaneously, and in the 

 same locality, at the same task of restraining the undue increase of 

 insect life during the period of the deposition of the lower Purbeck 

 beds." We may here trace another beautiful instance of the adapta- 

 tion of organic life to the conditions and circumstances in which it is 

 to be placed. These adaptations are of two kinds : the one which 

 shows us how those forms of life which have existed during long 

 periods of time, cease when the conditions necessary for their exist- 

 ence undergo such a change as to render them no longer suited to 

 the life they have hitherto maintained, — a phaenomenon which is 

 constantly brought under the notice of the attentive geological ob- 

 server. The second form of adaptation is that which points to the 

 commencement or creation of new forms, when new conditions have 

 been brought about agreeing with the requirements of their respective 

 existences. No doubt these latter are also of frequent occurrence, 

 but they more easily escape observation. It is seldom that the 

 palaeontologist or the zoologist has such an opportunity of seeing 

 cause and effect brought into such immediate juxtaposition as in this 

 case, where we find the insectivorous mammal there making his ap- 

 pearance where insect life was swarming, and when we may conclude 

 that the laws which regulated the existence of animal life required 

 the introduction of a fresh force to keep down the too rapid increase 

 or development of another, and to counteract its tendency to exceed 

 the functions for which it was intended. 



Our indefatigable colleague. Sir Philip Egerton, has contributed 

 even more than his usual quota of palichthyological information ; he 

 has in several papers described new species from various parts of the 

 world. Amongst these, his account of the fish remains from the 

 nummulitic limestone of the Mokattam Hills, near Cairo, is particu- 

 larly deserving of attention, as pointing out the union of the typical 

 characters of several families in one species, so as to render it doubt- 



