on the Species of Tra-p-door Spiders. 175 



same genus as Mr. Sells's Jamaica species, to whicli it is so closely 

 allied as scarcely to present any specific distinction beyond that of 

 size. The nests which I have seen have been about four inches 

 deep, slightly curved within, about three-quarters of an inch in 

 diameter ; the valve at the mouth not being circular, but rather of 

 an oval form, one side, where the hinge is placed, being straighter 

 than the other. The valve is formed of a number of layers of 

 coarse silk, in the upper layers of which are imbedded particles 

 of the earth, so as to give the cover the exact appearance of the 

 surrounding soil, the several successive layers causing it, when 

 more closely inspected, to resemble a small flattened oyster- 

 shell. The mouth of the nest is shelved off at the edge, so that 

 the valve, which is also* shelved off at the edge, falls into and 

 upon the orifice, and shuts it far more completely than if the 

 edges of the valve had been cut straight. The inner lining of the 

 nest and of the valve is pure white. The architect of this nest 

 I propose to name 



Aclhiojms cecUJicatorius. 



Piceo-niger, nitidissimus, subtus, cum pilis maxillaribus palli- 

 dioribus, abdomine obscuro, fusco sericeo, subtus ad basin 

 maculis 4 luteis, cephalo-thorace in parte postica semicir- 

 culariter vald^ impresso, pedibus fere sequalibus. $ 

 Long. Corp. lin. 12 — 14. 



This spider is of a pitchy black colour, and (with the exception 

 of the abdomen), very shining and polished ; the abdomen (which 

 is considerably larger than the cephalo-thorax and greatly elevated 

 and gibbose), is obscure, very finely sericeous, and of an vuiiform 

 dull brown black colour : the legs are clothed with hair and fine 

 bristles of various lengths, and the various joints are connected 

 together by a very pale whitish membrane, which gives them the 

 appearance of being annulated ; these limbs are nearly of equal 

 size, but variable in thickness ; the palpi are also ot considerable 

 length, and have all the appearance of a pair of feet, at least in 

 the female, which is the only sex I have seen either of this or the 

 Jamaica species. 



The cephalo-thorax is of an oval form, truncated behind, with 

 a slight elevation in front where the eyes are placed, and a very 

 deep semicircular impression behind the middle, open in front, the 

 part which is behind the impression being lower than that in front 

 of it; the eyes, eight in number, form two lines, four in each, the 

 anterior curved with the eyes at about equal distances apart, 

 the outer pair being largest, the posterior line is longer than the 



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