KUNGL. SV. VET. AKADEMIENS HANDLINGAR. BAND 5l. N:0 3. 29 
Sphenopteris (Onychiopsis?) psilotoides (StTokEs & WEBB) WARD. 
Pp TRSEEOR Sp 2hHöST 9, LOkTp 5 ge 202 
Hymenopteris psilotoides Stokes & WEBB 1824, p. 423; pl. 46, fig. 7. 
Sphenopteris Mantelli BRONGNIART 1828 a, p. 50. 
Onychiopsis Mantelli NATHORST 1890, p. 15. 
» » SEWARD/ 1894, Pp. £l:; pl: 206g. 1; ply3, fgs; 1—4; 
» psilotordes WARD 1905, p. 155; pl. 39, figs. 3—6. 
It is commonly agreed that Sphenopteris Mantelli is identical with Hymeno- 
pteris psilotoides SToKkES & WEBB. The former specific name has been generally used 
since its institution, but in 19035 Warp revived the older name. There may be 
disagreement in regard to the expediency of applying thus strictly the principle of 
priority in a case where it involves the rejecting of an old and much used name in 
favour of another, only a trifle older and generally forgotten. Once the older name 
has been revived from oblivion and employed, the case is different, the choice being 
between two names actually in use at the same time: it is difficult then to find any 
reason against accepting the older name. The species was transferred by NATHORST 
(1. ce.) to the genus Onychiopsis on account of the fructifications, which show a close 
agreement with those of Onychiopsis elongata (GEYL.) YoKE. described by YOKOYAMA 
in 1889. The species is represented in Patagonia only by sterile fronds, and it has 
therefore been preferred here to use the form-genus Sphenopteris. 
The best specimen is the one in pl. 2, fig. 9. It does not show any details, 
but it gives a good idea of the habit. It represents the upper portion of a bipin- 
nate (tripinnate) frond with very long, linear pinnae, directed forward at a rather 
narrow angle to the rachis. The pinnules are linear and directed forward, too; those 
of the upper pinnae are short and entire, those of the lower ones long and serrate 
or pinnatifid, becoming more dissected towards the lower end of the specimen. The 
frond was probably at least tripinnate, only the upper portion preserved being bi- 
pinnate. In pl. 2, fig. 10, is shown another specimen, consisting probably of a por- 
tion of a pinna from the lower part of the frond. In the upper part of the 
fragment, the pinnules are serrate to pinnatifid; in the lower, pinnatisect. The vena- 
tion is not clearly shown in any of the specimens. In pl. 5, fig. 20, is shown a por- 
tion of a fern-rachis without pinnules found associated with the specimens mentioned. 
It is probable that it belongs to this species. The small fragment figured in pl. 1, 
fig. 19, probably belongs to this species too. The uppermost pinnules seen are rather 
broader than usual, however, and less dissected. No accurate determination is pos- 
sible, but the specimen, which is the only one of this species from locality c, is best 
mentioned in this connection. 
Sphenopteris psilotoides is one of the characteristic species of the Wealden and 
has a world-wide distribution. It is known from different parts of Europe, from 
South Africa and from North America, and is replaced in Eastern Asia by the very 
closely allied Onychiopsis elongata (CEYL.) Yox. The vertical range is rather wide, 
