444 DE. Q. S. BEADY ON MEW OB 



abruptly to the posterior extremity, which is narrow and truncated ; surface of the 

 shell irregularly rugose, the ridges taking a transverse direction at the posterior end ; 

 a conspicuous polished tubercle on the anterior hinge. Length 1*3 mm. 



Hab. In rock-pools, Brighton, New Zealand. Two or three specimens only. 



The shell is somewhat like in general appearance to G. W. Miiller's genus Para- 

 cytheridea, but, so far as I have been able to observe, it does not agree with that genus 

 in minor details. The types described by Mr. Thomson were got among algae in 

 Otago Harbour. 



Cytheee trihstcula, sp. n. (Plate XLVII. figs. 16, 17.) 



Shell, seen from the side (fig. 16), subquadrangular, greatest height near the front, 

 and equal to about two-thirds of the length ; anterior extremity obliquely and not very 

 strongly rounded ; posterior very wide, almost rectangularly truncated, produced below 

 the middle, where it bears three short, stout, and blunt teeth ; dorsal margin sloping 

 rather steeply and irregularly from the front backward ; ventral almost straight for 

 about three-fourths of its length, where it forms a prominent abrupt angle, and thence 

 curves upward to the posterior extremity ; seen from above, the outline is lozenge- 

 shaped or subhexagonal (fig. 17), widest in the middle, the width being nearly equal 

 to the height ; extremities wide, truncated, and irregularly emarginate ; lateral margins 

 strongly arcuate, prominent in the middle, and converging rather steeply to each 

 extremity. Surface of the shell covered with large irregularly-angulated fossae ; a large 

 polished tubercle over the anterior hinge ; anterior margin fringed with coarse hairs. 

 Length "75 mm. 



Hab. Among weeds in Lyttelton Harbour. One specimen only. 



Genus Teachtlebeeis 1 , gen. nov. 



Shell beset with prominent nodules or spines. Antennules six-jointed, devoid of 

 spines, but bearing numerous slender setae; antennae four-jointed, that of the female 

 with a very short, falcate, urticating seta, which is absent from that of the male ; 

 mandible-palp with a small branchial plate bearing three upwardly-directed filaments, 

 a very short one directed downward, and one very minute, horizontal ray. The 

 remaining limbs as in Cythere ; in front of the first pair of legs in the male a pair of 

 one-jointed setiferous appendages. 



Teachtlebeeis scabeocuneata (G. S. Brady). (Plate XLVII. figs. 1-7, 18-25.) 

 Cythere scabrocuneata Brady (2), p. 103, pi. xvii. figs. 5 a-f; pi. xxiii. figs. 2 a-c. 



Shell of the male (figs. 1, 2), seen from the side, elongated, subquadrate, greatest 

 height near the front, and equal to rather less than half the length ; anterior extremity 



1 rpa\vs, rough ; Xefiqpls, a shell. 



