NOTICES OF NEW BOOKS. 373 



'Cambridge Natural History.' Vol. ii. Worms, Rotifers, and 

 Polyzoa. Macmillan & Co., Limited. 1896. 



This third volume of the Cambridge Natural History — vols, 

 iii. and v. having previously appeared — fully maintains the interest 

 and character of the series. No fewer than seven contributors 

 have assisted in the publication, which renders the task of an 

 adequate notice somewhat difficult in our limited space. 



"Flatworms and Mesozoa " have been entrusted to the pen 

 of Mr. F. W. Gamble. Besides a fully biological treatment and 

 a system of classification, the general zoological reader will find 

 many of those natural history narratives to which the pages of 

 this Journal are always open. We may instance as an example 

 a reference to the Liver-fluke of the sheep, Distomum {Fasciola) 

 hepaticum, which produces the disastrous disease liver-rot. This 

 " has a distribution as wide as that of a small water-snail, Limncea 

 trancatula, the connection between the two being, as Thomas and 

 Leuckart discovered, that this Snail is the intermediate host in 

 which the earlier larval, sporocyst, and redia stages are passed 

 | through, and a vast number of immature flukes (Cercarige) are 

 developed. These leave the Snail and encyst upon grass, where 

 they are eaten by the sheep. Over the whole of Europe, Northern 

 Asia, Abyssinia, and North Africa, the Canaries, and the Faroes, 

 [the Fluke and the Snail are known to occur, and recently the 

 former has been found in Australia and the Sandwich Islands, 

 i where a Snail, apparently a variety of Limncea truncatula, is also 

 found." 



The Nemertines are treated by Miss L. Sheldon. These 

 worms are common on the British coasts, and about forty species 

 have been recorded from this area. They " are often very 

 diversely and brilliantly coloured, the hues most commonly found 

 being white, yellow, green, deep purple, and various shades of red 

 and pink." There are also land and freshwater forms, in the last 

 of which there are certainly many new genera and species to be 

 discovered. Altogether a zoologist in want of a speciality might 

 well take up the Nemertine worms, and he will find Miss Sheldon 

 an excellent " coach." 



Mr. A. E. Shipley, one of the editors of the Series, writes on 

 " Threadworms and Sagitta." If these little animals are not the 



Zool. 4th ser. vol. I., August, 1897. 2 D 



