238 BOTANY OF THE VOYAGE 01 H.M.S. HEUALD. 
appearance, now induces me to view it aa a species ; but I cannot omit to notice its similarity to a form 
from the Philippines, named by me Kephrodiwn simplicifolium (Jour. Bot. vol. iii. p. 411), which I now 
"know to be the young state of a pinnate species. 
Plate L. Pigs. 1 and 2, portions of fertile frond ; 3, indusium ; 4, perfect sporangium, and 5, abortive 
sporangium : all magnified. 
1115. Nephrodium molle, E. Br. Prod. Fl. Nov. HoU. p. 149.— Prcsl, 1. e. p. 81.— J. Sm. Gen. 
Fil. 1. c. Common in the woods of the Isthmus. 
Universally difTused over the tropical and extra-tropical regions of both hemispheres.— v. v. in Hort. 
Kew. 
1116. Lastrea invisa, Presl, 1. c. p. 75.— J. Sm. Gen. Pil. 1; c. p. \%Z .^Aspidium invimm, Sw., 
Willd. 1. c. p. 224. Near Panama. 
Jamaica (Howard, "Wilson). 
1117. Lastrea macroura, Presl, 1. e. p. 75. — Aspldium macroui^m, Kaulf., En. Fil. p. 239. 
River Nuqui, Darien. 
Martinique (Sieber), A'enezuela (Otto). 
1118. Lastrea Sprengelii, Presl, 1. c. p. 75.~Aspldium Sprengelii, Kaulf., 1. c. p. 239. Chiram- 
bira, Darien. 
Martinique (Sieber), St. Vincent (Caley). — v. v. Hort. Kew. 
1119. Lastrea arguta, J. Bm.—Aspidium arguta, Kaulf., En. Fil. p. 342. Panama (Barclay). 
California (Barclay, Hartweg), Sandwich Islands (Barclay). 
In determining whether certain specimens represent distinct species, or are only forma of one, we 
are apt to be influenced by the idea that plants of a species are seldom foimd inhabiting regions widely 
separated and distant from each other. It is not till a number of examples of allied forms are brought 
before us, that we begin to see the error committt^d by many botanists when enumerating the plants of a 
particular region or countr}', in forming new species, without ascertaining -whether they may not be already 
described from some other region. In the present case, although I have "adopted Kaulfuss' name of arguta, 
still I see no way of distinguishing it from the eastern forms (X. macrocarpa and ehugata), which, on col- 
lating with others, including the well-known L. Filial-Mas, exhibit a series difficult to recognize as distinct 
species; the latter, even in this country, presents aspects as well entitled to rank as species as its 
foreign allies. 
1120. PoLYSTiCHUM vesHtum, Presl, 1. c. p. 83. — Aspidium vestitnm, Sw., Willd. I. c. p. 261. — 
Blume, En. Fil. Jav. p. 163. Volcano of Chiriqui, Veragnas. 
V. V. Hort. Kew, 
The group to which this species belongs may be considered as truly cosmopolitan, inhabiting elevated 
regions within the tropics, and extending to high latitudes of the temperate regions of both hemispheres, 
and assuming, according to the nature of the climate, various aspects ; the extreme forms may readily be 
described as distinct species, but the transition from one form and aspect to another is such as to render it 
difficult, if not impossible, to determine them otheru'ise than as geographical allies of the European forms 
kno^\'n by the names of Polgstichum hhatum and P. acuUatum. 
1121. Cyclopeltis semicordata, J. Sm., Bot. Mag. vol. Ixii. (Comp. p. 36). — Lastrea semicor- 
