HARDWICKE'S SCIENCE-GOSSIP. 



221 



little Anurea cochlcaris also suffered from the ravages 

 of this voracious and energetic vixen. 



From the mastax a long tube leads down to the 

 stomach, which is filled with a brownish granular 

 matter. A little under the stomach, at a short 

 distance up from the foot, is the contracted vesicle, 

 a transparent bladder, which fills and empties itself 

 in forty seconds. The length of mature specimens 

 is from 1 ^ to nearly T J 5 of an inch. 



Its life is vigorous but short, its whole lifetime, 

 from babyhood to old age, being not more than forty 

 hours. 



It flourished, and continued to be prolific in the 

 pond for four weeks, when it suddenly disappeared. 

 I have not caught a single individual since. It may 

 again appear at the same season this year, but this 

 peculiarity of sudden disappearance and reappearance 

 is observable in all the synchreta, as well as in other 

 rotifers. 



John Hood, F.R.M.S. 



Dundee. 



resemblances, rather than by reference to the analysis 

 of their composition. This should be a study by 

 itself, and instances should be taken from the examples 

 already classified on a popular basis. 



Our object being now to extend Howard's list by 

 noting more species and giving them characteristic 

 names, we will leave the question of composition 

 for separate treatment. In passing, we may note 

 that "cumulus" has a very varied structure, from 

 fine rain mist to distinct ice crystals. The writer has 

 seen a mock-sun formed in a drifting mass of this 

 cloud. It is most frequent in autumn and winter, 

 and is, for the most part, an attendant upon, and 

 prognostic of, storms. It is frequently seen in the 

 equinoctial gales. The size and height of this 

 cloud are often remarkable, and remind one of 

 Ulysses on his raft, when he uttered the exclamation — 

 'Oioictiv vecp€(ffai irepicTTecpei ovpauov evpw ; for they 

 have a most formidable and threatening aspect. 



The edges of this form are curling, with many 

 small indentations, and it is best seen in the zenith, 



Fig. 122.— Outline of High Rain Clouds. 



ON SOME TYPES OF STORM-CLOUD. 



No. II. 



" T TIGH Rain-Cumulus." — The expression 

 -Ll "rain-cumulus," as distinguished from 

 "Snow-C," and "Hail-C," suggests a fresh classifi- 

 cation of clouds upon the basis of their composition, 

 i.e. the form, temperature, crystalline property, &c, 

 of their component particles. But it is practically 

 more convenient, and more to the purpose of forecasts, 

 to have the cataloguing of the various forms done in 

 relation to their general associations and characteristic 



when the sides of the cloud are viewed from 

 beneath. 



It is generally accompanied by wind, and has a 

 rapid motion, forming in the front of an advancing 

 rain-storm," and spreading outward in a vast "pal- 

 lium" with outline of this character. (See sketch.) 



The space between the lower portion of the cloud 

 and the earth is often very great, the upper part being 

 of great altitude. 



The sky is often of a very mixed character when 

 these vast sheets of cumulus are seen. The deluge of 

 rain that visited Derbyshire on August 31st, 1887, 



