Mr. BiackwaLv's Descriptions of new Species of Spiders. 627 
14. Theridion albens. Albidum; ovalibus 2 parvis obliquis e lineis tenuibus 
nigris efformatis prope abdominis medium ; cephalo-thorace fascià ob- 
scurà medianà; oculis in anteriore cephalo-thoracis parte positis, inter- 
mediis quadram referentibus ; labio triangulari acuto. 
Length of the female zth of an inch; length of cephalo-thorax u; breadth 
35; breadth of abdomen 35; length of an anterior leg 75; length of a 
leg of the third pair g. 
Cephalo-thorax glossy, compressed before, convex above, with a slight inden- 
tation in the medial line of the posterior region. Mandibles small, conical, 
vertical. Maxille 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, third 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 their 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, but a 
small, oblique oval, formed by a fine, black line, occurs near the middle 
of the upper part of the abdomen, 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 1837, among strawberry plants growing in my father's garden 
at Hendre House, near Llanrwst. 
15. Theridion callens. Cephalo-thorace pallidè flavescenti-brunneo, lateribus 
maculisque pluribus triangularibus quarum maxima centrali nigris; ocu- 
lis in anteriore cephalo-thoracis parte, intermediis quadram referentibus, 
seriei anterioris in tuberculo positis; mandibulis saturatè brunneis ; 
VOL. XVIII. 4N 
