466 CATHARINEA TENELLA ROHL. IN BRITAIN. 



dark reddish brown base. Cells of the exothecium for the most part 

 quadrate, with strongly thickened longitudinal walls. Peristome 

 teeth large (0-35 mm.), minutely papillose, basal membrane 

 (0-03 mm.) and axils of the teeth yellowish. Spores 0*014 to 

 0-021 mm., yellowish, almost smooth. Fruit, August and 

 September." 



C. tenella occurs in Scandinavia, Germany, Belgium, Austro- 

 Hungary, Switzerland, and France, and so might have been 

 expected to occur in Britain. It has, in fact, been already recorded 

 as British from three localities : Strensall Moor, Yorkshire, Loch 

 Goil Head, and between Ben Lawers and Killin ; but all the speci- 

 mens from these places are, according to Dr. Braithwaite, only forms 

 of C. undulata (L.) Web. Mohr., or C. undulata var. minor (Hedw.) 

 Web. Mohr. (see Braithw. Brit. Moss Flora, i. 41). 



The distinguishing characters of C. tenella are the dioicous in- 

 florescence, in which it is essentially distinct from C. undulata, 

 from the ordinary form of which it differs ixi the oblong-lanceolate 

 (not longly Ungulate) leaves, not or only slightly undulate, and 

 nearly smooth at back, the few often interrupted lamellae, and the 

 short oblong slightly inclined but not arcuate capsule. C. angustata 

 differs conspicuously in the numerous lamella, smaller leaf-cells, 

 &c. C. crispa has taller stems, and distant broader leaves, with 

 laxer areolation. 



It may be mentioned here that the character emphasized by 

 Limpricht {loc. cit. 593) as separating C. crispa from C. tenella and 

 C. angustata does not always hold good. C. crispa is stated to have 

 the nerve smooth at back, the other species to have it spinose 

 towards the apex. In the specimens, however, of C. crisjm that 

 I have examined — Mr. Dixon tells me that the same is also 

 his experience — the nerve frequently bears towards the apex, at 

 back, a few distant spines, just as is the case in C. tenella and 

 C. angustata. 



Although the ordinary form of C. undulata is very different from 

 C. tenella, the var. minor approaches the latter species so closely at 

 times that the difference in inflorescence seems to be the only 

 character separating them. As a rule, however, C. tenella has 

 more oblong leaves, fewer lamella, and lamina smoother at back ; 

 while the var. minor generally shows here and there signs of the 

 leaves becoming elongate and more undulate, and capsule arcuate, 

 &c. I have, however, seen leaves on some specimens of the var. minor 

 {e.g. the specimen of McKinlay's Ben Lawers plant in the Kew 

 Herbarium) which are identical in shape, areolation, the very 

 few low lamellaB, and absence of spines at the back of the lamina 

 with those of C. teyieUa, and the capsule very similarly shaped. 

 C. undulata var. minor certainly wants further study, and observa- 

 tions on growing plants with reference to the inflorescence would 

 be extremely valuable. 



The first specimens (fig. 1) collected of the Bedgbury Wood 

 C. tenella attracted attention by the short stems, terminating in a 

 female flower (without any appearance of having proliferated from 



