■Mr. Blackwall's Descrijifions of new Species of Spiders. (527 



1-1. Theridion alhens. Albidiim ; ovalibns 2 parvis obliquis e lineis tenuibiis 

 nigris eftbnnatis prope abdominis medium ; ceplialo-tliorace fascia ob- 

 scura mediaiicâ ; ociilis in antenore cephalo-thoracis parte positis, inter- 

 mediis quadram referentibus ; labio triangulari acuto. 



Length of the female ^th of an inch; length of cephalo-thonix 3-^ ; breadth 

 gig ; breadth of abdomen -^; length of an anterior leg -^; length of a 

 leg of the third pair 3^. 



Cephalo-thorax glossy, coTnpressed before, convex above, with a slight inden- 

 tation in the medial line of the posterior region. Mandibles small, conical, 

 vertical. Maxillae slender, obliquely truncated at the extremity, on the 

 outer side, and inclined towards the lip, which is triangular, and pointed 

 at the apex. Sternum heart-shaped. First pair of legs the longest, then 

 the fourth, which a little exceeds the .second in length, tliird pair the 

 shortest. Tarsi terminated by three claws; the two superior ones are 

 curved and pectinated, and the inferior one is inflected near its base. 

 The palpi have a curved claw at tiieir extremity. Abdomen thinly co- 

 vered with hairs, very convex above, projecting greatly over the base of 

 the cephalo-thorax. The general colour of this spider is whitish, l)ut a 

 small, oblique oval, formed by a tine, black line, occurs near the middle 

 of the upper part of the abilomen, on each side of the medial line ; the 

 sexual organs also are black, and an obscure band of a darkish hue ex- 

 tends along the middle of the cephalo-thorax. Eyes seated on black spots 

 on the anterior part of the cephalo-thorax; the four intermediate ones 

 form a square; the other four are disposed in pairs on the sides of the 

 square, the eyes constituting each pair being contiguous and placed ob- 

 liquely on a slight protuberance. 



The minute spider from which the foregoing description was made was dis- 

 covered in July 183/, among strawberry plants growing in my father's garden 

 at Hendre House, near Lhuirwst. 



15. Theridion callens. Cephalo-thorace pallidè flavescenti-brunneo, lateribus 

 maculisque pluribus triangularil)us quarum maxima centrali nigris ; ocu- 

 lis in anteriore cephalo-thoracis parte, intermediis quadram referentibus, 

 seriei anterioris in tuberculo positis ; mandibulis saturate brunneis ; 



VOL. XVIII. 4 N 



