Tree Trap-door Spider from Trinidad. 409 



But it further differs from this last-named specimen in having 

 the ccphalotliorax less elevated, a smaller distance between 

 the two ocular tubercles, the eyes on the posterior tubercle 

 set more closely together, and in possessing fewer spines on 

 the labium. 



The nest of this species, which was sent with the specimen, 

 appears to resemble that of P. rastratus from Bahia. It is a 

 short tube permanently closed at the bottom, with a hinged 

 door at the entrance formed of closely woven silk threads, and 

 perfectly smooth inside. The length of the tube from the 

 hinge-margin to the bottom is only about twice the greatest 

 diameter of the aperture. 'J'he surface by which it was 

 attached to the tree-trunk is tolerably flat ; the free surface, 

 on the contrary, is strongly convex and thickly covered, as 

 also is the door, with particles of bark. The shape of the 

 cavity corresponds to that of the outside and of the door. 

 The door, which is slender and with upturned edges, is wider 

 one way than the other, i. e. its width from the hinge to the 

 margin opposite to it is less than the width taken along a 

 line at right angles to this measurement, it opens outwards 

 and closes by the elasticity of its hinge. When closed the 

 plane of its outer surface meets that of the trunk of the tree 

 at an angle of about 45°. 



Note 1. — In the nest of Actinopus scalops, which Mr. Hart 

 sent with the specimens of this species, the hinge of the door 

 is strengthened and protected by thick tough layers of 

 greenish silk, so that the area above the hinge projects far 

 above the rest of the surface of the door (PI. XIX. fig. 3). 



Note 2. — Mr. Hart forwarded with the specimens of 

 Argiope argentata examples of the cocoons of that species. 

 These cocoons show an interesting variation in colouring, 

 being either bright yellow or green on both sides or green on 

 one side and vellow on the other. 



EXPLANATION OF PLATE XIX. Figs. 1-3. 



Fig. \. Pseudidiops Hnrtii, sp. n., nat. size. 1 a. Lateral view of cara- 

 pace. 1 b. Lateral view of upper part of carapace, to show 

 arrangement of eyes and disposition of sette. 1 c. Labium. 

 1 d. Pseudidiops rastratus (Cambr.), for comparison with tig. 1 6. 



Fiy. 2, Nest of Pseudidiops Hartii, sp. n. 



Fig. 3. Nest of Adinoims scaloj)s, Simon. 



