516 



SCIENCE 



[N. S. Vol. XXVI. No. 668 



as stated in the introductory remarks, " there is 

 on every side an insuflBciency of data," and con- 

 sequently it is not possible to solve many of the 

 fundamental problems pertaining to the group. 

 The study of variation is inseparable from ex- 

 perimental physiological investigations, for these 

 are a necessary foundation for the understanding 

 of variation (p. 6 ) . 



The author then goes on to distinguish he- 

 tween gametic and vegetative variation, and 

 to outline the methods wherehy these might 

 be studied experimentally. He expresses the 

 hope that the necessary investigations may be 

 undertaken by the marine biological stations. 

 Under Pontes compressa (pp. 174-193) there 

 is given a full account of twenty types of 

 variation, called forms and subforms. 



The variation appears to be continuous, but 

 with a nvimber of definite secondary modes, should 

 they be plotted into a specific curve. . . . We have 

 no facts by which it could be ascertained whether 

 the differences are of gametic or vegetative origin. 



Antarctic Pteropod Mollusca. — In the re- 

 port of the British National Antarctic Expedi- 

 tion (1907), Sir Charles Eliot discusses the 

 Pteropods of the southern seas, and calls at- 

 tention to the fact that " in both the Arctic 

 and Antarctic seas the predominant, and as 

 we approach the Poles probably the only 

 Pteropods are closely allied, or even identical 

 epeeies of Limacina and Clione." The dis- 

 tribution of these forms is interrupted by a 

 wide zone in which they do not occur, none 

 having been recorded from within thirty de- 

 grees either north or south of the equator. 

 Sir Chas. Eliot remarks : 



I confess that I have seen no explanation of 

 these facts which appears to me satisfactory. Our 

 knowledge of the direction in past ages of ocean 

 currents which must have largely determined the 

 distribution of pelagic forms is slight, and our 

 record of fossil Pteropods is very imperfect (p. 3). 



The Lizard-genus Leiolopisma. — Dr. L. 

 Stejneger, in his recent admirable revision of 

 -the Reptiles and Amphibians of Japan,^ gives 

 an account of Leiolopisma laterale (Say), a 

 lizard which in North America inhabits the 

 lower Austral zone east of the Eocky Moun- 

 tains, but is not found at all in the west. It 



= Bulletin 58, U. S. National Museum, 1907. 



reappears in Asia, occurring over a large area 

 in China, and exists also in the Riu Kiu 

 islands. The Chinese animal has been sepa- 

 rated as L. reevesii (Gray), but Boulenger 

 failed to find any distinctive characters to 

 separate it, and Dr. Stejneger " upon the 

 most searching comparison " has also utterly 

 failed to discover any difference. The re- 

 maining species of the genus belong to the 

 Old World. In speaking of the Scincidse in 

 general, Dr. Stejneger says : " Many species 

 have an enormous geographic range, owing to 

 the ease with which they may be accidentally 

 transported," but there is no reason to sup- 

 pose that the distribution of L. laterale should 

 be explained in that way. Probably many 

 genera of lizards are of great antiquity. 

 When recently at the Museum of Comparative 

 Zoology I was shown by Mr. Samuel Henshaw 

 a small lizard perfectly preserved in amber. 

 Instead of being some strange extinct form, 

 as one might have expected, it had all the 

 appearance of a modern Gekko, and pre- 

 sumably belongs to that genus. It is scarcely 

 necessary, of course, to refer to the fact that 

 the case of Leiolopisma parallels several others 

 known among plants, the molluscan Philo- 

 mycus, etc., though the absolute specific 

 identity is very remarkable, especially in a 

 vertebrate. 



A Mollusc New to Ireland. — Mr. J. W. 

 Taylor' has published a very interesting ac- 

 count of the discovery of Vitrina elongaia 

 (Draparnaud) in Ireland. It is a species 

 which occurs commonly in the mountain re- 

 gions of Central Europe, and also in Spain, 

 and Mr. Taylor thinks it formerly had a much 

 wider distribution, but has been driven out of 

 many regions by stronger or more dominant 

 species. Its survival in Ireland he attributes 

 to the easier conditions (from the standpoint 

 of the Vitrina) existing there. 



A Grass Common to Ecuador and Guate- 

 mala. — In a recent account of some Guate- 

 malan plants,* Dr. B. L. Robinson and Mr. 

 H. H. Bartlett call attention to the discovery 

 of the anomalous genus of South American 



' Irish Naturalist, August, 1907. 

 ' Proc. Amer. Acad., June, 1907. 



I 



