SCIENCE-GOSSIP. 



26: 



bhe head " ("'). Grassi, however, who has studied 

 two wingless Embiids, has maintained that the 

 webs are spun by the first pair of legs,' of which 

 t lie first tarsal segment is enlarged and contains 

 glands whose secretion escapes by orifices at the 

 tips of setae interspersed between short spines 

 that are placed on the sole (-"). 



With regard to the use of the webs, Lucas be- 

 lieved them to serve as traps for insects, on which 

 he supposed the Embiids to feed. Yet he does not 

 appear to have seen insects entangled ; and it is 

 improbable that these feeble creatures are pre- 

 daceous. There is reason to believe that they 



(19) Westwood, Gardeners' Chronicle (u.s.), vii. (1877), pp. 

 S3-4. 



(20) Grassi (1893), quoted by Sharp. I.e. 



Live chiefly on vegetable matter; and M'Lachlan 

 remarks f li.it. the silken tunnels of OUgot 

 miehaeli arc net- at all of the nature of spiders' 

 snares, but arc similar to the webs of many c: 

 pillars. Another suggestion made by Lucas is 

 thai the threads may serve to warn the Embiids of 

 the approach of enemies ; ami this may well be 

 true; but no doubl the webs are mainlj valu; 

 as a covering and pla.ee of abode. It is inten 

 ing to find, moreover, that according to Grassi the 

 silken tissue is intimately associated with the 

 insects' progression ; and that, in conformity with 

 their mode of life within the galleries of web, the 

 two posterior pairs of feet are much modified . 

 sessing papillae and a comb which act upon the silk. 

 {To he continued.') 



AN INTRODUCTION TO BRITISH SPIDERS. 



By Frank Percy Smith. 



(Continued from page 236.) 



GENUS CERATINELLA EMERTON. 



' I ""IBIAE of fourth pair of legs without spines or 

 A with a very small one. Tarsi very little shorter 

 than metatarsi. Caput of the male not elevated to 

 any extent. 



Caratinella scabrosa Cb. ( Walckenaera sca- 

 ■brosa, in " Spiders of Dorset.") 



Length. Male nearly 2 mm. 



The palpal organs are large and complicated, and 

 have connected with their extremity a strong coiled 

 spine. 



Ceratinella brevis Wid. ( Walckenaera de- 

 fressa Bl. ) 



Length. Male 1.8 mm., female 2 mm. 



This uncommon spider may be distinguished from 

 C. scabrosa Cb. by the smaller size of the palpal 

 organs and the spine at their extremity. The cephalo- 

 thorax, sternum, and abdomen are minutely punctured. 



Ceratinella brevipes Westr. ( Walckenaera 

 brevipes in " Spiders of Dorset.") 



Length. Male 1.5 mm., female 1.7 mm. 



This spider may be distinguished from C. brevis 

 Wid. by its smaller size and by the greater height of 

 the clypeus compared with the width of the ocular 

 area. 



GENUS WIDERIA SIMON. 



The curious little spiders included in this genus 

 have the labium recurved at the extremity, the 

 maxillae short and broad, and the cephalo-thorax 

 strongly impressed in the region of the caput. There 

 is often a very distinct cephalic lobe in the male. 

 The posterior row of eyes is strongly curved, its 

 convexity being directed backwards. The tibiae of 

 the fourth pair of legs are each provided with a very 

 minute spine. 



"Wideria antica Wid. ( Walckenaera antica in 

 " Spiders of Dorset.") 



Length. Male 1.7 mm., female 2.2 mm. 



In this species the cephalic lobe viewed from 

 presents an oval appearance, two eyes being visi": le 

 upon it. 



The tibiae of the first two pairs of legs are darker 

 than the rest of the joints. 



In front of the caput are two processes curving 

 upwards. 



This spider is not uncommon, and has been fre- 

 quently taken in the neighbourhood of London. 



"Wideria cucullata Koch. ( Walckenaera cucul- 

 lata in " Spiders of Dorset.") 



Length. Male 1.7 mm., female 1 -8 mm. 



In this species the radial joint of the male palpus is 

 of a very curious form. When viewed from above il 

 is seen to consist of two branches, one of which it 

 curved inwards to such an extent as to point aim st 

 directly backwards. This spider is rare. 



GENUS WALCKENAERA Bl. 



In this genus the posterior row of eyes is straigl t, 

 or slightly curved, its convexity being directed 

 forwards. The eyes are restricted to the central part 

 of the caput, which is rather broad. The form of the 

 cephalic region varies greatly in different species, and 

 in the male is, in some cases, elevated in an extra- 

 ordinary manner. 



"Walckenaera acuminata Bl. 



Length. Male 3.5, female 4.2 mm. 



This species can be recognised ai once b 

 enormous elevation of the caput oi the male, which 

 is produced into a slender pedicle uponi which the 

 eyes are placed. It appears to be somewhat un- 

 common. 



K .; 



