686 



BIRD MITES. 



Meaopon pallldum. 

 Nlrmus argulus. 



Dochphorus cygni. 

 Goalodes falclcornls. 



the last-mentioned species, except that there is more red in it. Moreover, it can be 

 distinguished by the antennae, which have the second joint the longest and the third 

 acute. The eyes, too, are large and prominent. 



THE four creatures represented in the accompanying illustration are parasitic on 

 birds. The species shown in the upper left-hand corner is unpleasantly familiar to 

 poultry-keepers, swarming among the feathers to such a degree that the hands are 

 often covered with these parasites when the fowls are plucked or even lifted up. They 

 cling very tightly, and are not easily brushed away, as their bodies are smoothly pol- 

 ished, and offer scarcely any resistance. The color of this species is pale straw. 



The upper right-hand figure represents 

 a parasite found on the common swan and 

 other aquatic birds, such as the bean 

 goose and Bewick's swan. It is colored 

 after a rather peculiar fashion. The 

 head, thorax, and legs are bright chest- 

 nut, smooth and shining ; the abdomen 

 is white, except the first segment, which 

 is of the same color as the thorax. 

 There is also a chestnut spot on the third 

 segment, and a row of short liver-colored 

 bands runs down each side. 



At the lower left-hand corner is seen a 

 parasite which is not very plentiful, but 

 which is found on various birds, such as 

 the rook, the raven, and blackbird. It 

 has a hard shelly surface, and is marked 

 with numerous dark bars. The last figure 

 represents the SICKLE-HORNED TICK, so 

 called from the shape of its antennae, 



which are rather large, flattish, and curved. It is a pretty species, its squared 

 head being of a light chestnut color, and highly polished. The abdomen is broad, 

 rather flat, and of a light tawny yellow, barred with deep red, and having the last seg- 

 ment of the same color as the head. It is parasitical upon the common peacock, and 

 may almost invariably be found after the death of the bird congregated in tolerable 

 numbers about the base of the beak. 



IN the accompanying illustration are seen some details of the characteristic portions 

 of many Arachnida, most of which have been casually mentioned in the preceding pages. 



The two upper rows exhibit the manner in which various types of eyes are arranged, 

 and are valuable as showing how important are the eyes in distinguishing one genus 

 of spiders from another. The bold staring eyes on the right-hand side of the upper 

 row are those of the genus Nops, and, as far as is known, are unique among spiders. 

 They are large, black, glittering, and bear no slight resemblance to the glasses of " bull's- 

 eye " lanterns. The centra! figure represents the eyes of the genus Salticus, or Hunt- 

 ing Spider, and on the extreme left are the eyes of Lycosa, or Wolf-spiders, which are 

 set in a manner almost precisely the reverse of the preceding. 



Passing to the right-hand figure of the second row, we come to the cephalothorax 

 and eyes of the new British spider, Dysdera erythina. The central figure gives a pro- 

 file view of the cephalothorax of a male Walckenaera acuminata, showing the long, 

 slender, vertical process of its termination, and the manner in which the eyes are 

 disposed upon it. On the left hand of the same row is shown the elevated front of 

 the cephalothorax belonging to the genus Hersilia, showing the remarkable manner in 

 which the eyes are arranged. 



The third row contains some specimens of grasping organs. On the right hand is 

 shown the under surface of the base of mandibles, belonging, I believe, to the genus 

 Linyphia. The severe illness of the artist prevents me from ascertaining whether that 



. ! 



