SCIENCE- GOSSIP. 



CLASSIFICATION OF BRITISH TICKS. 



By Edward G. Wheeer. 



(Continued from page 365.) 



Classification. 



7T1HE family of the Ixodidae are broadly divided 

 -*- by Professor Neumann into two sub-families 

 — I. Argasinae ; II. Ixodinae. 



I.— THE ARGASINAE. 



The Argasinae are plainly distinguishable from 

 the Ixodinae by the absence of either dorsal or 

 ventral shields in either sex, also by the situation 

 of the rostrum, this being placed beneath the 

 ■cephalothorax, covering it as with a hood ; except in 

 the larval state, when it is often terminal. In the 

 pupal state it often partially projects. The palpi 

 are plain, cylindrical, and the joints differ little 

 from each other. Legs nearly equal in length. 

 Colour varying from earthy yellow, or red, to dark 

 "brown. Sexual orifice situated between the two 

 first pairs of legs. In general dimensions the male 

 is smaller than the female. 



The genera of the Argasinae are (a) Argas ; (b) 

 •Ornithodorns. 



Genus ARGAS Latreille 1796. 

 11HYNCHOPRION Hermann 1804. 



Body flat, general contour round or oval : narrower 

 in front than behind, and larger behind the 



Argas reflexus. Male. 



haunches of the fourth pair of legs. The sides of 

 the body thin, or slightly thickened like a cushion. 



Tegument of body finely shragreened, except in 

 certain spots which are covered with thin round- 

 ish discs, more or less numerous and variously 

 situated : the most important always forming 

 a radiating series, of which the central one is 

 longest both on the back and beneath. Eyes absent. 

 Of this genus M. Neumann describes eleven 

 species, some of which are doubtful. Of these 



/ 



• - v 



/■■ 



Fig. 3. Argas reflexus. Female. 



Argas reflexus and A. 

 found in England. 



vespertilionis have both been 



Argas reflexus Fabricius. 



Synonyms: Aearus reflexus Fabricius, 1794; 

 Aearus marglnatus Fabricius, 1794 ; Argas reflexus 

 Latreille, 1796 ; RhgneJioprioneoluvibae'Ilerm. 1804. 



Adults : length, female from 5 mm. fasting, to 

 8 mm. when distended, fig. 3 ; male, 4 mm. fig. 2. 

 The thin tegument of the female allows the brown 

 or dark violet tint of the digestive organs to be 

 seen, the margin always remaining yellowish 

 (marginatus) and a little raised (reflexus) when 

 fasting... The male is uniformly brown. The tarsi 

 of all the legs have a prominent dorsal knob at the 

 extremity. The hypostome is roundei at the end, 

 and often a little dilated in the middle. Dorsal sur- 

 face of the body finely shagreened. The discs are 

 larger towards the centre and smaller and more 

 numerous within the margin. The latter is finely and 

 evenly folded, or wrinkled all round the body. Two 



B 4 



