BRITISH SPIDERS. 91 



CASE does not perform by diving, as is the case with the water spider, 

 but by means of the aquatic plants, down whose stems it crawls. 

 Its capability of existing for some time beneath the surface of the 

 water is often the means of saving its Hfe ; for, when it sees an 

 enemy approaching, it quietly slips under the raft, and there lies 

 in perfect security until the danger has passed away. There 

 is living in the same localities a closely-allied species, the 

 Pirate Spider (Lycosa piratica), which has similar habits, chasing 

 its prey on the water, and descending as well below the sur- 

 face. It does not, however, possess the habit of making a 

 raft. 



It carries its cocoon about with it, like other spiders. 



No. i8. Trochosa CINEREA {Fab.), Lycosa allodroma, ^/.— 18. Enlarged figure. 



A rather large grey and white species. It has been found in 

 Wales. 



Family SPHASID^. 

 A separate family has been made for a single transition- 

 species Oxyopes lineatus, which unites three groups, the Lyco- 

 » sidae, the Thomisidae, and the Salticidse. It has the principal 

 characters of the first, the appearance of some of the second 

 (Philodromus), and the habits of the third, of leaping suddenly 

 on its prey. 



Jfo 19. Oxyopes lineatus {Latr.), Sphasus lineatus, Bl. — 19. Enlarged figure. 



It is light brown, with pale markings on the back, and black 

 spots on the legs. 



Family SALTICID^E. 

 This family derives its name from its habit of leaping on its 

 prey {Saltus, a leap). They run with great velocity, and move 

 sideways with ease. They are easily recognised by their oblong 



