i6o 



SCIENCE- GOSSIP. 



Desmids may often be kept alive in a bottle of 

 water for a considerable time. On lately examining 

 a bottle of material collected last September, I found 

 a nnmber of Etiastrum verrucosum still living. 



There are many points in connection with the 

 manipulation of desmids which I have not tried, and 

 I am in hopes that the present papers may lead other 

 microscopists to give their experiences of them. For 

 example, the use of formalin as a fixative, the best 

 reagents for staining desmids, etc. It would be 

 particularly interesting to learn whether the gelatinous 

 envelope of such .species as Hyalotheca can be stained. 



or the tip of Closterium showing the motile bodies in 

 their cavity. Apart, however, from the undoubteil 

 possibility of improving on the technique, or varying 

 it to suit individual taste or available appliances, it is 

 certain that, given a suitable locality, a great deal of 

 real enjoyment can be got out of collecting and pre- 

 paring these tiny little plants, without the risk of ■ 

 exterminating or increasing the rarity of species 

 which attaches to the netting of butterflies, or the 

 collection of phanerogams and ferns. 



{ To be iOiitimted, ) 



AN INTRODUCTION TO BRITISH SPIDERS. 



By Frank Percy Smith. 



i^Continjied froiu Page 330. ') 



FAMILY CLUBIONIDAE. 



' I "HE spiders contained in this family are of a more or 

 less cylindrical form. The eyes are widely spread 

 across the front part of the caput, the clypeus being 

 rather narrow. The arrangement of the spinners is 

 very different from that in the Drassidae. The 

 Clubionidae usually live in silken tubes, from which 

 they slip with wonderful rapidity when disturbed. 

 The pubescence on the abdomen often hides to a 

 great e.xtent the real colour of the integument, but 

 this becomes at once apparent when the spider is 

 immersed in spirit. 



GENUS CLUB ION A LATR. 

 The eyes in this genus are arranged in the form of 

 a crescent, the posterior laterals forming the ex- 

 tremities. The maxillae are long, the extremities 

 being somewhat enlarged. The spiders which this 

 genus comprises are very similar to one another in 

 appearance, and their differentiation is often a matter 

 of difficulty. The male palpus, particularly the radial 

 apophysis, and the vulva are, of course, almost certain 

 clues to the identity ofa spider ; but as a large majority 

 of the specimens captured are immature, these indica- 

 tions in that case do not e.xist. If the eyes are care- 

 fully measured, and also the distances between them, 

 the species may be distinguished in most instances. 

 I have made drawings of the eyes of several species ; 

 and it will be noticed that the most tangible differences 

 are the relative distances between the eyes of the 

 front row, and also the distance between the hind 

 centrals, compared with their diameters. 



Clubiona grisea L. Koch. (Clubiona holo- 

 scriica Bl. ) 



Length. Male 8.4 mm., female 12 mm. 



Cephalo-thorax brown with pale hairs. Legs 

 reddish-yellow, with some spines. Abdomen of a 

 pale brown tint, with a dense covering of grey hairs. 



(i) This series of articles on Kritish Spiders commenced in 

 SCIENCE-Uossn', Xo. 67, December 1899. 



The radial joint of the male palpus is of a most 

 curious form, and almost indescribable. This spider, 

 which is not very common, is usually found among 

 the low herbage of damp ditches. 



Clubiona terrestris Westr. (Clubiona aina- 

 7-antha Bl. ) 



Length. Male 8 mm. , female 9 ram. 



Cephalo-thorax pale reddish-brown. Legs reddish- 

 yellow, with spines. Abdomen reddish-brown, 

 clothed with hairs, and having an indistinct marking 

 of a darker hue on the upper side. This spider is 

 not uncommon amongst low herbage and debris. 



Clubiona reelusa Cambr. 



Length. Male 6 mrn. . female 7 mm. 



Cephalo-thorax with some vein-liki? markings upon 

 it. Radial joint of male palpus with a very prominent 

 apophysis. C. fornwsa Bl. is probably an immature 

 specimen of tliis spider. 



Clubiona lutescens Westr. 



Length. Male 6 mm., female 6.5 mm. 



This rare spider is similar to C. terrestris Westr. , 

 but maybe distinguished by the form of the radial 

 apophysis and the palpal organs ; the fakes are also 

 much longer. 



Clubiona negleeta Cambr. 



Length. Male 6 mm., female 6.3 mm. 



This rare spider may be distinguished from its 

 congeners by the possession of a long, curiously 

 twisted spine connected with the palpal organs. 



Clubiona pallidula Clk. (Clubiona epimelas 

 Bl.) 



Length. Male 10 mm., female 10.5 mm. 



Cephalo-thorax of a greenish tint, suffused in front 

 with brown. Abdomen reddish-brown, with small 

 markings of a dark brown colour. The species is 

 common and generally distributed. 



Clubiona eortiealis Wlk. 



Length. Male 12 mm., female 12.5 mm. 



