The Zoologist— June, 1869. 1705 



is another widely diffused shell, and extremely variable in colour and 

 size. I have observed many young in the top branches of a high tree 

 just felled, on the very top of the mountains, in Yateras. It seems to 

 be a high climber, which may account for its comparative rarity, fully 

 grown and alive. I have met with very few. 



Cylindrella is largely represented in Cuba, more than eighty species 

 being enumerated in the latest catalogue. Most of the species are 

 extremely local ; several, so far as is now known, being restricted to 

 localities of a few yards square, or to a few rods. Doubtless other 

 localities will be discovered for many of them. A few, as C. Poeyana, 

 C. elegans and C. irrorata, are much more widely spread, but probably 

 not one extends through the whole island as does Achatina fasciata. 

 But what is most noteworthy is the remarkable tenacity of life pos- 

 sessed by many species. Some have lived for months, and even years; 

 and, unless closely confined, they will crawl forth on the return of 

 warm, damp spells of weather, getting into the wrong boxes and 

 creating sad confusion. 



A Covtribution towards the Life-history of Cecidomyia persicarice, 

 Linn. By Albert Muller, Esq. 



The eggs of the spring generation of this midge are laid in the 

 months of April and May by females which have hybernated in their 

 cocoons in the larval state, in small batches of from three to ten, on 

 the under margins of the leaves of Polygonum amphibium, Linn, 

 [var. terrestre). They are pale orange, oblong, rounded off at both 

 ends, and piled one against the other in a recumbent position, in a 

 similar way to that in which we see small pebbles settled down in the 

 beds of rapidly-flowing brooks: the larvae hatch after a day or two, 

 according to the weather; they are then almost transparent, 'and of a 

 very pale hue ; their shape elongated and depressed. As they are 

 getting older they assume the well-known shape of nearly all Ceci- 

 domyian larvae; the body slightly truncated behind, increases in 

 breadth towards the middle and tapers gradually to a point ; their 

 colour is now orange, and remains so for the whole term of their larval 

 life. At first they are rather lively when disturbed, but their rapid 

 growth soon renders them obese and more or less helpless. Under 

 the influence of their irritating action,* the inhabited leaf-margins 



SECOND SERIES — VOL. IV. 2 P 



