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XLI. Description of a Species o/'Arachnida, hitherto uncha- 

 racterizcd, belonging to the Family Ai'aneidre. By John 

 Blackwall, F.L.S. S^c* 



Tribe, TuBiTEL^, U^treille. 

 Genus, Dysdera^ J 



Dysderci Latrcillii. 



THE upper part of the cephalothorax is deep black, the 

 under part being of a dark reddish-brown colour. The 

 abdomen is almost cylindrical, very soft, hairy, and of a pale 

 livid brown colour, each extremity inclining to yellowish- 

 white above; the four exterior mammula; or spinners are 

 nearly equal in length. The legs, which are rather long, are 

 marked with broad bands of brown and yellowish-white; the 

 first pair is the longest, then the fourth, the third pair being 

 the shortest; the two superior tarsal claws are deeply pecti- 

 nated. The eyes are seated in the anterior part of the head ; 

 they are six in number, nearly equal in size, and form a small 

 oval open in front, somewhat resembling a horse-shoe in 

 fifTure. The mandibles are vertical ; the maxillse are long and 

 dilated at the base externally, where the palpi are inserted : 

 the lip is elongated, and gradually decreases in breadth from 

 the base to the apex. In the male of this species, the sexual 

 organs are situated near the termination of the palpi, on their 

 under side, and are bent abruptly backwards ; they are of an 

 oval form, and have a delicate curved process near their ex- 

 tremity. 



Length, from the anterior part of the head to the extremity 

 of the abdomen, |th of an inch ; length of the cephalothorax 

 J-th ; greatest breadth of the cephalothorax abouty':jth ; length 

 of an anterior leg fths. 



The above description is taken from a male spider ; indeed, 

 I have not yet been so fortunate as to procure a single speci- 

 men of the other sex. The first individual I met with was in 

 a hedge at Oaklands, about two miles south from Llanrwst, on 

 the Denbighshire side of the vale of Conway, North Wales. 

 I afterwards found two other specimens in the crevices of a 

 stone wall inclosing the ornamental grounds immediately ad- 

 joining Gwydir House, on the Caernarvonshire side of the 

 same vale. The manners and occonomy of this species are at 

 present unknown to me, but I hope soon to have an opportu- 

 nity of investigating them. 



I have carefully compared the new spider with a fine speci- 

 men of a male Dysdera erythrina, captured in Manchester by 



* Communicated by the Author. 



