6 NATURAL SCIENCE. July. 1895. 



hand. The cubic centimetre, the French milHHtre, is about the size 

 of French dice, which are a shade smaller than English dice. The 

 litre is nearly a cube of four inches. It is about a pint and three- 

 quarters, which Mr. Donisthorpe says is what we ihink of as a long 

 drink. 



The Distribution of Scale-Insects. 



A recent note by Professor T. D. A. Cockerell {Pvoc. U.S. Nat. 

 Mus., vol. xvii., pp. 615-625) gives a summary of the numbers of genera 

 and species of scale-insects (Coccidae) known from various parts of 

 the world. It appears that our ignorance of these creatures is as yet 

 very great. A few areas have been well marked. Principally 

 through the labours of Mr. Maskell, 108 species are recorded from 

 Australia, and seventy-seven from New Zealand. Professor Cockerell 

 thinks that the Coccidae of the latter islands are better known than 

 those of any European country. The recorded Palaearctic coccid 

 fauna is believed to number about 200 species, while the Nearctic list 

 numbers 127, the development of economic entomology in North 

 America naturally accounting for attention to such a destructive 

 family there. In our own country the group is being investigated 

 by Messrs. J. W. Douglas and R. Newstead. Mr. Cockerell him- 

 self has paid much attention to scale-insects in the West Indies, whence 

 come most of the 124 recorded Neotropical species, Brazil contribut- 

 ing some half-dozen to the total. From the entire Ethiopian and 

 Oriental regions together fewer insects of the family are known than 

 from the island of Jamaica. We see from this summ.ary what an 

 immense field for research lies open to naturalists who will pay atten- 

 tion to these minute insects. The sedentary habits of the females 

 render inquiry into their distribution and means of dispersal of special 

 interest, while no branch of zoology is more important to the gardener 

 and the fruit grower. 



Irish Freshwater Sponges. 



In a recent number of the Irish Naturalist (vol. iv., pp. 122-13 1) 

 Dr. R. Hanitsch enumerates six species of Spongillidai from Ireland, 

 the British fauna containing but four species. Three of these occur 

 in Ireland, the other three sponges, all from the west coast of the 

 latter country, being also North American species. Dr. Hanitsch 

 would not solve this interesting distributional problem by supposing a 

 former extension of the sponges over the whole northern hemisphere; 

 he believes that their gemmules could readily have been carried across 

 the Atlantic by winds, ocean currents, or birds. In some remarks on 

 the European distribution of the Spongillidffi, Dr. Hanitsch notices 

 their extreme rarity in Southern Europe. Only one species is known 

 from the Iberian peninsula (N. Portugal), two from the Italian, while 

 none at all have been found in the Balkan. 



