EURHYNCH1UM. 421 



The longer, strong nerve is the distinguishing character of this species, and the 

 more broadly-pointed leaves and somewhat firmer areolation, besides the difference in 

 the form of the fruit, must be taken into account ; and the wider patches in which it 

 grows usually give it at once a different habit. I find a plant, however, in 

 Northamptonshire, which from its short nerve must be referred to E. atrviseium, 

 but growing in wide patches, and in the areolation and form of capsule also coming 

 near E. Teesdalei ; and I am obliged to conclude that some of the characters held to 

 ■distinguish the two are not always safely to be relied on. 



* * Seta smooth. 



10. Eurhynchium tenellum Milde (Hypnum tenellum Dicks. ; 



Rhynchostegium tenellum B.&S., Schp. Syn. ; H .algierianum 



Brid.) (Tab. LIV. G.). 



In very low, yellowish, very soft and silky tufts, not half-an- 

 inch high ; stems densely intricate, about an inch long, prostrate, 

 with numerous, erect or curved very short branches. Leaves 

 erecto-patent, rarely sub-secund, not erect nor appressed when 

 dry, shining and silky , about f-line long, very narrow, linear- 

 lanceolate, gradually tapering to a long attenuated point, margin 

 plane, almost entire ; nerve distinct, reaching high in the acumen 

 (rarely ceasing just above the middle) ; cells extremely narrow, 

 linear-fusiform, 10-15 times as long as broad, at extreme base 

 short, lax, sub-rectangular, not distinct at angles. Seta about 

 •J-inch long ; capsule small, oval, somewhat variable in form and 

 direction; lid longly rostrate. Autoicous. 



Var. j3. scabrellum Dixon n.var. (H. scabrellum Mitt. ined.). 

 Seta more or less scabrous. Growing usually on wood. 



Hab. Rocks and stones, most frequently in calcareous districts. Frequent. 

 The var. /3 on wood and trunks of trees on calcareous soil, sometimes on stones ; nr. 

 VyXmAgt ( Benbow ) ; : nr. Lewes (Nicholson) ; Hurstpierpoint (Mitten). Fr. spring. 



A very distinct species, easily recognised by its low, silky tufts and extremely 

 narrow, tapering, entire leaves. The seta is rather longer and the fruit rather more 

 conspicuous than in the three preceding species. E. cunrisetum is the only one 

 which could be taken for it, having narrower, more tapering leaves than the other two, 

 and the inflorescence autoicous ; but the smooth seta and the still narrower, longer, 

 entire, silky leaves identify the present plant, at least in its typical and ordinary form, 

 without difficulty. 



The var. meridionale Boul. , the form with the nerve ceasing at about the middle 

 of the leaf, has not, so far as I am aware, been recorded from this country. 



The var. scabrellum is a very remarkable and highly interesting form, demon- 

 strating as it does the slight importance to be placed on the smoothness or otherwise of 

 the seta as a systematic character for separating genera or groups of species (though as 

 an artificial distinction it may often be very useful). I have received numerous speci- 

 mens from Mr. Nicholson and from Mr. Benbow, which all show the same 

 characteristics and indicate that, in the districts in which it occurs, the form is widely 

 distributed and even abundant ; and the same is the case, according to Mitten, 

 at Hurstpierpoint. The setae show great variability as to roughness, some 

 being as scabrous as in E. curvisetum and the allied species, while others on the 



