Mr. "VV. H. Benson on the Pteropodous Genus Hyalsea. 21 



which are about as wide again as those between the four spots 

 before mentioned. A number of minute white hairs are spread 

 over the back and sides^ causing silvery reflexions in certain 

 lights ; the edge of the projecting base of the abdomen is also 

 fringed VA'ith a row of stiff black bristles, eight or ten in number. 

 Undcr-surfacc of the abdomen dark brown, with two wide longi- 

 tudinal yellow stripes. 



The male only differs from the female in being moi'e slender 

 in form and brighter in colour. The palpal organs of the spe- 

 cimen which I found were not fully developed, as it had not 

 undergone its final change of integument. 



I discovered an adult female and an immature male of this 

 very pretty little spider, in August 1860, on the ground among 

 brush-wood at Newton Purcel, near Bicester, Oxon ; and I 

 captured several young individuals of the same species on pre- 

 vious occasions in the same locality. 



IV. — Notes on the Pteropodous Genus Hyalsea, and Description 

 of a new Species. By W. H. Benson, Esq. 



The localities of the tracts inhabited by the shell-bearing Ptero- 

 poda are mostly given by systematic writers and other observers 

 in such general terms, that a few notes on the subject may prove 

 useful to those who collect or study these interesting forms. I 

 commence with the genus Hyalcea, including Diacria, Gray. 



Only eleven recent species of Hyalcea are admitted by Souleyet 

 in his edition of Bang's folio work published in 1855. Including 

 H. flava, D'Orbigny, which appears to be a distinct species, the 

 number of well-ascertained species will amount to thirteen, the 

 whole of which, with a number of varieties, were procured in the 

 ship 'Malcolm/ in 1834-35, and during a passage from Bengal 

 to the Cape in 1846, in the ' Gloriana.' My observations may 

 assist in determining the value of the specific distinctions between 

 one or two forms regarding which authors have difitred, and in 

 proving that a species described by Morch as new may be referred 

 to one previously known. 



Hyalaa tridentata, Lamk. 

 This large globose species, which may be detected at sunset 

 flitting at the surface of the ocean in its usual jerking mode of 

 progression, was taken at intervals from 10° S. lat. and 31° W. 

 long, in the Southern Atlantic, through 39|° S. lat. and 33° 

 E. long, in the Southern Ocean, 37° S. lat. "and 75° E. long., 

 33° S. lat. and 81° E. long, to 6° S. lat. and 87° E. long, in the 

 Indian Ocean ; and a small variety (or more probably a distinct 



