136 THE GENUS SCAPHOSEPALUM PFITZER. 



graph of that genus, in 'Folia Orchidacea.' In 1855 a second 

 species appeared, and Eeichenbach reverted to liis earlier opinion, 

 and called it Masdevallia ochthodes: and successive species have 

 been described under Masdevallia. Of the correctness of this view 

 I have long felt a doubt, on account of certain anomalous characters, 

 which do not altogether correspond with either of tbe two genera. 

 The character which separates Masdevallia from Pleurothallis is 

 that in the former the base of the dorsal sepal is united with the 

 lateral pair to form a tube, of variable length in the different species, 

 while in the latter there is no such union, consequently no tube. 

 There is no other character which applies to all the species that 

 can be relied upon to separate the two genera. 



The remarkable amount; of uniformity which prevails throughout 

 the very numerous species of these two genera does not altogether 

 apply to the little group in question, which Professor Pfitzer now 

 proposes to separate, under the name Scaphosepalum (Engler and 

 Prantl., ' Naturliche Pflanzenfamilieu,' vol. i., Orchidaeese, p. 139), 

 in allusion to the scooped-out or boat-like arrangement of the 

 united pair of lateral sepals. Tbe following are its essential 

 characters : — The flowers are invariably inverted as compared with 

 the two genera named — that is, the lateral sepals and the lip are 

 invariably uppermost, while the odd sepal and the column are 

 underneath. The dorsal sepal is either free or so nearly so that the 

 union is barely perceptible ; while the lateral pah* are united for 

 some distance into a curiously curved and concave body, and then 

 sharply turned outwards into a pair of diverging tails, which differ 

 greatly hi shape in the different species. The lip is a very curiously 

 curved and crumpled body, which is not easily described in a few 

 words, but, like the other characters named, totally unlike any- 

 thing seen in either Pleurothallis or Masdevallia. In short, Scapho- 

 sepalum differs more from either of these two genera than they do 

 from each other, and therefore I think its separation fully justified. 

 The exclusion of this group from Masdevallia leaves that genus far 

 more homogeneous in character, as well as more strictly separable 

 from Pleurothallis. I now think that the anomalous species I 

 described some time ago (Gard. Chron. 1888, pt. 2, p. 178) as 

 Masdevallia platyrhachis must be referred to Pleurothallis. 



The following are the species : — 



1. S. anchoriferum. Masdevallia anchorifera Echb. f., in Gard. 

 Chron,, 1884, i. p. 577. — Costa Pica. It is allied to 8. ochthodes. 



2. S. breve. Masdevallia brevis Echb. f., in Gard. Chron., 1883, 

 ii. p. 588. — British Guiana, Eoraima district. Allied to the pre- 

 ceding species and 8. macrodactylum. 



3. S. gibberosum. Masdevallia gibberosa Echb. f., in Gard. 

 Chron., 1876, i. p. 8 ; Bot. Mag., t. 6990. — New Granada. 



4. S. macrodactylum. Masdevallia macrodactyla Echb. f., in 

 Gard. Chron,, 1872, p. 571.— New Granada. 



5. S. ochthodes Pfitz,, in Engl, and Prantl., Natiirl. Pflanzen- 

 fam., i. Orch. p, 139. Masdevallia ochthodes Echb. f., in Bonplan- 

 dia, iii. (1855), p. 70. — New Granada, discovered by Wagener, near 

 Ban Pedro and Turmero, at an altitudo of 6000 feet. 



