IMPERFECTLY-KNOWN SPECIES OF OSTRACODA. 439 



coarse hairs (fig. 3), and the dorsal surface bears patches of very short, rigid, and 

 closely-set hairs (figs. 2, 11), which have dilated subglobnlar or crutch-shaped apices. 

 Length 1*05, height *85 mm. Shell of the male (fig. 4) elongated, not unlike that of 

 Philomedes, nearly twice as long as high ; surface-markings scarcely so pronounced as 

 those of the female. Length 1*1 mm. The limbs of the female differ scarcely at 

 all from those of S. capsula, which has been fully described by G. O. Sars and 

 G. W. Miiller. Post-abdominal lamina? narrow, its four marginal ungues very slender, 

 and increasing progressively in length from the first to the last, which is at least four 

 times as long as the first (fig. 10), their inner margins sparingly spinulose. The 

 mandible of the male (fig. 8) differs from that of the female in being more profusely 

 setiferous, and in having only one, instead of three, terminal ungues ; the antennule 

 (fig. 5) has on the penultimate joint a cushion-like prominence which bears a dense 

 brush of innumerable long fine hairs ; extremity of the vermiform limb truncated, and 

 without the pairs of hooks which are found in the female. Copulative organ (fig. 12) 

 ending in two stout and blunt chitinous hooks. Secondary branch of the antenna 

 (fig. 6) three-jointed, geniculated ; inner margin of the second joint bearing at the base 

 two very long and stout spine-like setse; terminal joint slightly thickened at its base, 

 blunt and angularly bent. Post-abdomen like that of the female. 



Hah. Plentiful in a dredging, from 1-5 fathoms, in Lyttelton Harbour. 



The extremely hirsute character of the shell and the peculiar cushion-like patches of 

 knobbed hairs, forming a sort of interrupted nimbus round the edges when seen 

 dorsally, are very characteristic. But the surface-sculpture is not easily seen while 

 the shell is immersed, and when removed from liquid it very speedily shrivels and 

 loses its proper markings. The genus Nematohamma Brady & Norman was founded 

 on male specimens of a Sarsiella, the relation of which to the female form was 

 then unknown. 



Saesiella hispida, sp. n. (Plate XLV. figs. 13, 14.) 



Shell membranous, thin and flexible, seen from the side subrhomboidal (fig. 13), 

 height equal to two-thirds of the length ; anterior extremity narrowed, rounded ; 

 posterior much wider, subtruncate, sloping very steeply, and terminating in a long 

 conical beak ; dorsal margin almost flat in the middle, whence it slopes gently toward 

 the front ; near its hinder end it is distinctly sinuated and terminates in an abrupt 

 angle; ventral margin boldly arcuate, with a slight sinuation (antennal notch) near 

 the anterior extremity ; seen from above (fig. 14), subquadrate, oblong, sides nearly- 

 parallel, but indented near the middle, obtusely rounded in front, rectangularly- 

 truncated behind, with a large median mucronate process. Shell densely hispid, and 

 on the dorsal aspect bearing patches of short, rigid, clubbed hairs ; surface of the 

 valves flexuously ribbed in a longitudinal direction. Length l - 5 mm. 



Hab. Akaroa Harbour ; dredged in a depth of 6 fathoms. 



3 M 2 



