UNIONIDA. 161 
Length, 2°5 ; height, 1-45 inch (from Reeve’s figure.) 
Rivers in the North Island and Lake Taupo. (Dieffenbach.) 
Ashburton River and Hutt River. (F. W. H.) 
U. aucklandica, Gray, Dieff N.Z, ii., p. 257; Reeve, Conch. 
Le., f- 156. Shell oblong and rather thick, rounded in front, and rather 
obliquely truncated behind, covered with a thick olive periostraca ; 
umbo black, decorticated, cardinal teeth low, blunt, oblique, hinder 
lateral teeth laminar, far off ; the inner surface pearly, purplish near the 
umbo, greenish on the hinder edge (Gray.) Shell oblong-ovate, thin, 
compressed, concentrically densely thread striated ; umboes radiately 
wrinkle-ridged ; sides rounded ; anterior very short ; posterior obscurely 
convexely angled (Reeve.) 
Length, 2:2 ; height, 1°15 inch (from Reeve’s figure.) 
Bay of Islands and Auckland (Dr. Sinclair.) Lake Takapuna, 
Auckland. (F. W. H.) 
U. zelebori, Dunker, Retse der Novara, Moll., p. 2, f. 28. Shell 
oval-oblong, rather thin, sub-ventricose, rather compressed towards the 
base ; anterior end shortly rounded ; posterior linguiform, finely con- 
centrically striated: epidermis thin, pale olive, sub-horny ; umboes 
swollen, turned forward, inclined and rugosely angled; upper margin 
arched, sub-excavate in front ; lower margin straight, sub-sinuated in the 
middle ; cardinal teeth compressed, acute, crenated, laterals sub- 
straight, the superior in each valve smaller as usual ; anterior muscular 
impressions deep, unequal, the smaller sub-reniform ; interior iridescent 
below the umbones, faint and yellowish (Dunker.) 
Length, 2; height, 1 ; thick, ‘64 inch. 
Hardly distinguishable from the last in shape, but the dorsal margin 
does not ascend from the umbo, but runs parallel to the ventral 
margin. 
River Wairarapa. (F. W. H.) 
U. hochstetteri, Dunker, Mal. Blatt. viii., 1861, . 153; Reeve, 
Conch. Ic., f-.463. Shell thickish, depressed, very inequilateral, narrow 
and very short in front, broadly biangular, and somewhat winged 
behind, of a uniform blackish olive, very indistinctly sub-verrucose in 
the middle, elsewhere unsculptured ; ligamental edge curved and rising; 
hinder area concave, no lunule; nacre bluish white, variegated with 
olive; primary teeth somewhat transverse ; lateral teeth elongated, 
much raised, and obliquely truncated at their extremities (Reeve.) 
Length, 21; height, 1°5 inch (from Reeve’s figure. ) 
Distinguished by its great height, and the posterior end being 
truncated almost perpendicularly. 
Lake Taupo and River Waikato. (Hochstetter.) 
I have never seen this species. 
U. lutulentus, Gould, U.S. Ex. Ep., xii. p. 428, f. 542; Reeve, 
Conch. Ic., f. 122 and f. 386. Shell somewhat squarely oblong, very 
compressed, anterior side moderately rounded, posterior slopingly ex- 
