4 OBSERVATIONS ON THE SPECIES OF POTTIA. 



Wilson (Bryol. Brit. p. 98) candidly admits that lie " dares not pronounce 

 P. Starkeana and P. mbudula distinct ;" yet has kept the two forms in 

 the presumed distinct genera. The scabrous calyptra escaped the notice 

 of the authors of the ' Bryologia Europsea.' 



4. P. Heimii, Hedw., easily distinguished by its leaves, varies greatly 

 in the length of its capsule, but although frequent search has been made 

 for a peristome, in promising specimens none has been found. 



5. -P. lanceolata, Hedw. (^Anacalypta lcinceolata~), although described 

 with entire leaves, has always some trace of minute crenation near where 

 its nerve is excurrent from the apex of its leaves. This species is very 

 variable in its peristome, when gymnostomous it is probably Gymnosto- 

 mnm intermedium. Turner, and of Schwsegrichen, Supp. t. 7, a form com- 

 monly referred to P. truncata, from which it may be distinguished by the 

 crenation of the margin and rough cells of its leaves. The Desmatodon 

 Giiepini (Bryol. Europ. DesmatodoH, t. 4) can hardly be other than a more 

 complete form ; no character is given in the description by which it could 

 be safely distinguished. 



6. P. Cfvspitosa, Bruch, is unlikely to be confounded with any other 

 species excepting P. Starkeana, and from this it differs immediately in the 

 smooth calyptra. 



7. P. trimcata, Bryol. Europ., may be truly Gymnostomnm. truncatnm, 

 Hedw. Fund. t. 5, but Hedwig has figured and described his species as 

 dioicous, — a fact which seems to have been overlooked ; it is certainly the 

 G. trimcatum oi t\\e Bryol. Germanica, t. 9. f. 8. This species has acute 

 entire leaves with smooth cells ; it varies greatly in its capsule, which is, 

 however, always as wide at the mouth as it is lower down, and its usual 

 form is turbinate ; forms with an elongated capsule are probably in herba- 

 ria confused with the gymnostomous state of P. lanceolata. Mueller 

 says in his ' Synopsis,' p. 554, that he has met with the peristome. 



8. P. littoralis, n. sp. ; leaves oblong-subspathulate, obtuse or acute, 

 the lower ones pale, the upper green ; cells in the upper part of the leaf 

 about half the size of those of P. truncata, hence more obscure, smooth ; 

 lower cells oblong, pellucid ; nerve excurrent, longer in the inferior leaves ; 

 capsule oblong- oval, mouth less than the greatest diameter; operculum 

 rostrate, slightly twisted ; male flower bud-like. Hab. Aldrington, near 

 Brighton, Sussex, growing with P. Heimii, also at Hastings. The oval 

 capsule, not dilated at the mouth, gives this Moss a greater similitude 

 to P. lanceolata than to P. truncata, but from this it difiers in the smooth 

 leaves. I formerly mistook this Moss for P. crinita, from which it differs 

 in the quinquefarious arrangement of its leaves, and much shorter and 

 more slender nerve, as well as in its smooth cells. 



9. P. asperula, n. sp. ; leaves obovate-spathulate, acute, but not acu- 

 minate ; nerve excuiTent into a short point, upper cells rounded, rather 

 obscure, each with several elevated points, lower cells oblong, smooth, 

 pellucid ; capsule oval ; operculum rostrate ; cells slightly twisted ; an- 

 theridia naked in the axils of comal leaves. Hab. Henfield, Sussex, near 

 Penzance, in several places, Mr. Curnow ; Jersey, M. Piquet ; also in 

 Wilson's Muse. Brit, with P. truncata, n. 90. This has more obscure 

 leaves than P. truncata, and when they are bent over under the microscope 

 the roughness of the cells is easily perceived. The capsule is not so wide 

 at tha mouth as it is about its middle. It is possible that this species 

 may be sometimes confused with P. lanceolata, when that species is gym- 

 nostomous, but it has many points of difference. 



