THE BRITISH NATURALIST. 



83 



of this pest is to plant bananas among the trees, these being a 

 favourite food of this species, are carefully searched, &c. The slugs 

 when adult are above three inches in length, and about an inch and a 

 quarter broad, sole much narrower than the body. The typical form 

 is white or whitish, but these now under consideration are dark brown 

 obscurely mottled with darker brown above ; white, more or less 

 tinged witri yellow below. Mr. Cockerell proposes for this form the 

 varietal name coffecz. 



Notes. 



We quote the following from the " Nautilus," whose editor culled 

 it from a daily paper in the States. It is too great a gem of the 

 average journalistic science to be lost : — " It is generally supposed to 

 be a sign of wet weather when snails go about without their shells. 

 One species of snail never takes its walks abroad except when rain is 

 at hand. Some climb trees two days before a down-fall, settling upon 

 the upper-side of the leaves, if a storm is to be of short duration, but 

 taking shelter on the under-side if it is to last some time. Still other 

 snails turn yellow before rain, and blue when it is over." 



Mr. Sykes has an interesting paper in the " Proceedings Dorset 

 Natural History and Amateur Field Club " for 1892, on some mon- 

 strosities of Littovina rudis, all more or less scalariform, which he is 

 inclined to attribute to growths of weed in the suture of the shell, 

 while the building is still in progress. A peculiarity of some of these 

 shells is that they appear at first to be sinistral, and it is only on close 

 examination that one finds them to be dextral with the last whorl bent 

 upwards right above the spire. The Littorinas in question came from 

 drift in the Fleet near Weymouth, and belong to the var. tenebvosa. I was 

 fortunate enough to find a small genuinely reversed specimen there 

 about 4 years ago. Very few of our marine species have occurred 

 with the spire reversed. Besides this one, L littorea has several times 

 been procured from Billingsgate market in this state. The best known 

 shell however which " reverses " (to borrow a dancing term) is Bucci- 

 num undatum — a species subject to many " sports "• — and it is moveover 

 not so very uncommon. Most of the specimens come from the fish 

 dealers. Its congener, Fusus antiquus, is very scarce reversed, though 

 this is well known to be the usual form in the Red Crag, where dextral 

 specimens are quite a rarity. No explanation seems to have been 

 offered of this curious alteration from a sinistral to a dextral state of 

 normal growth. We can, of couse, find somewhat parallel cases at 

 the present day, e.g., in the genera Pavtula, Achatinella, or Amphidromus, 

 where the two states frequently exist side by side in what are 

 undoubtedly shells of one species, but there is here no sign of a 

 transition from the sinistral to the dextral (or vice versa) in progress, 



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