694 ORCHIDES. [Corysanthes. 
hood-shaped, arched over the lip. Lateral sepals and petals small, 
linear-subulate, seldom more than 4 as long as the lp. Lip large, 
involute, the margins meeting behind the column and enclosing it, 
orbicular-cordate when spread out; base with a rounded auricle on 
each side ; apex truncate, entire or very slightly denticulate ; disc 
with a thickened patch covered with deflexed hairs. Column short, 
stout, curved, swollen in front at the base. 
Norts Istanp: Auckland—Kaitaia (Mongonui County), R. H. Matthews ! 
July-August. 
Clearly allied to C. oblonga, but the flower is larger, the lateral sepals and 
petals much reduced in size, the upper sepal narrower at the base and more 
hood-shaped at the top, and the margin of the lip is not coarsely fringed. 
3. C. oblonga, Hook. f. Handb. N.Z. Fl. 266.—Variable in size, 
12in. high. Leaf sessile, #-l}in. long, ovate-oblong, apiculate, 
rounded or cordate at the base, thin and membranous, conspicu- 
ously veined when dry. Flowers small, shortly peduncled, solitary 
or very rarely two together, about +in. long, reddish-purple ; bract 
rather large, sometimes foliaceous, erect. Upper sepal narrow, 
concave, oblong when spread out, obtuse or apiculate, arched over 
the lip. Lateral sepals and petals filiform, +?in. long. Lip 
involute, the margins meeting behind the column and enclosing it, 
broadly semicordate when spread out ; base with a rounded auricle 
or orifice on each side; apex truncate, coarsely toothed or fimbriate, 
centre of disc with minute dentiform papille. Column short, stout, 
curved to the front, with a swelling at the base.—Nematoceras 
oblonga, Hook. f. Fl. Nov. Zel.i. 250, t. 57B. 
NorrH anp SoutH IsLANDS, STEWART IsLAND: Not uncommon on moist 
shaded banks from the North Cape southwards. Sea-level to 2000 ft. Sep- 
tember—November. 
4, C. rivularis, Hook. f. Handb. N.Z. Fl. 266.—Very delicate 
and membranous, 1-24 in. high. Leaf sessile, $2 in. long, ovate or 
oblong-ovate, acuminate, deeply cordate or almost 2-lobed at the 
base, very thin and membranous, veins conspicuous, reticulated. 
Flower shortly pedunculate or sessile between the lobes of the leaf, 
4-Lin. long; bract narrow, acuminate. Upper sepal narrow, con- 
cave, arched over the lip, gradually tapering into a long filiform 
point. Lateral sepals and petals filiform, 1—2in. long, the petals 
usually exceeding the sepals. Lip involute, the margins meeting 
behind the column and enclosing it, broadly ovate-cordate when 
spread out; base with a rounded auricle or orifice on each side; 
upper portion curved forwards and downwards, acuminate or apicu- 
late, margins undulate, entire. Column very short, stout, erect.— 
Nematoceras rivularis, Hook. f. Fl. Nov. Zel. i. 251. 
NortH anp SoutH Isuanps, Stewart IstAnpD: In damp wooded ravines 
from the North Cape southwards, but often local. Sea-level to 2000 ft. 
September—November. 
