40tj Dr. W. T. Caiman on the 



the basal margin may form a continuous curve with the 

 occludent margin or it may meet it in a distinct angle at the 

 umbo ; the angle which it forms with the chord of the occlu- 

 dent margin varies, although it is always noticeably greater 

 than a right angle ; the basal margin may be straight or 

 slightly concave or convex ; and it may be equal to or shorter 

 than the base of the carina. 



In Gravel's specimen and in the others that have been 

 dissected the filamentary appendages (fig. 3), although 

 varying in number, resemble those found in the holotype; 

 there are usually some six or seven pairs of very long 

 appendages on the anterior part of the tergal surface of the 

 prosoma, followed by a number of shorter ones, some of which 

 mav, as in the specimen figured, be reduced to papillae. 



The asymmetry of the mandibles observed by Hoek and 

 again found in Gravel's specimen is by no means constant ; 

 as a rule, both mandibles have three teeth in addition to a 

 bidentate inner angle, but smaller intermediate teeth may be 

 developed in some or all of the intervals between the larger 

 teeth. 



The rami of the first pair of cirri (tig. 3) have respectively 

 ten and eleven segments, at least one of the proximal segments 

 being, as usual, very indistinctly defined. '1 ne posterior 

 cirri in large specimens have a small sixth pair of spines in 

 addition to those observed in the holotype. The caudal 

 appendages (fig. 3) may exceed one-fourth of the length of 

 the peduncle of the sixth cirrus. 



The largest of the specimens from the coast of Cuba 

 measures 23 mm. in length and 10'5 mm. in breadth of 

 capitulum. 



Megalasma (Gly/.>tehisma) sp. 



The specimen here recorded was found, as mentioned above, 

 among the syntypes of P. carinatum. The capitulum 

 measures 9*5 mm. in length by 4*6 mm. in width. It differs 

 from all the specimens described above in the following 

 characters : — 



(1) The cuticle of the capitulum is everywhere beset with 

 short fine setae. 



(2) The straight basal margin of the scutum is at right 

 angles to the chord of the occludent margin, and is a little 

 longer than the concave basal margin of the carina. 



(3) There are no filamentary appendages. 



(4) The caudal appendages are extremely short, not more 





