327 



Labellum almost oblong; contracted laterally about the 

 middle; margins slightly crenulat^d, but entire; about 

 3" 75 mm. long with an average width of 1 mm., but expanding 

 beyond the contraction to a maximum breadth of 15 mm. ; 

 lamina 5-nerved, with three callosities; a large anterior mesial 

 callus, usually hastate or oval-hastate, extending almost to 

 the tip; posteriorly two calli usually oblong-oval in shape, 

 but owing to absorptive changes often assuming various 

 crescentic or cuspidate forms, each occupying the basal area 

 between the middle and the marginal ner\e. 



Anther with minute point, its apex considerably higher 

 than the rostellum. Auricles large, prominent and rounded 

 with small basal lobe on posterior margin, reaching to about 

 the same level as the rostellum. 



Hah. — Diamond Tree School, near Jarnadup, W.A., 

 Miss I. Knox-Peden, December, 1918; Greenbushes, W.A., 

 Dr. R. Pulleine, 8/12/17; Albany, W.A., Dr. A. Syme 

 Johnson, 4/12/19. 



This plant approaches most nearly to M . media, Br. In 

 media, however, there are only two callosities on the lamina, 

 both of which are basal and usually comma-shaped ; there is 

 no true anterior callosity, but its place is taken by two large 

 oval-shaped groups of tuberculated glands; similar glands 

 fringe the anterior margins of the labellum, which is 

 emarginate at the apex. In the new species the labellum is 

 not retuse or emarginate but is truncate. Further, its lateral 

 petals are linear-falcate with blunt tips, whereas in media 

 they are linear-oblong or linear-lanceolate. The following 

 clavis shows the relation of the new species to other members 

 of the genus: — 



[Note. — The measurements are all taken from dried 

 specimens.] 



Lateral sepals recurved or revolute in mature 



flowers. 

 Labellum with 3 well-defined callosities on 



lamina, viz., 2 basal (lateral) and 1 



anterior (mesial). 

 Labellum emarginate at tip; lateral 



petals relatively wide, oblong - oval, 



much shorter than lat. sepals; dorsal 



sepal wide, concave, exceeding 2 mm.. 



long M. porrifolia 



Labellum truncate ; petals linear-falcate, 



at least as long as lat. sepals ; dorsal 



sepal broad, exceeding 3 mm. long ... M. truncata 

 Labellum with 2 definite lat. callosities at 



base, no anterior callus. 

 Labellum entire, no tuberculate glands 



on margins or surface; dorsal sepal 



broad, barely exceeding 2 mm. long ... M. parviflora 



