OF THE THIRD TANGANYIKA EXPEDITION. 181 
rounded-hemispherical shape, and sometimes a second heterocyst is developed 
after the trichome has shifted a short distance from the base of the sheath. 
Forma angustior et longior. 
Crass. fil. ad bas. 4-5°5 ш; crass. trich. 34-8 
130 p. 
Tanganyika.—Epiphytie on Cladophora inconspicua, е 
young branches very thickly, in a few fathoms of water, Niamkolo. 
Тр; long. toto fil. usque 
lothing some of the 
337. CALOTHRIX PARIETINA, (Kätz.) Thur. in Ann. Sci. Nat. 6° sér. Dot. 1. 
(1875) p. 381; Born. § Flah. l. c. T° sér. Bot, iñ. (1886) p. 366. 
Crass. fil. ad bas. 13:5-19 №; crass. trich. 175-975 д. 
Victoria Nyanza.—On rocks just below the water-level, Bukoba (17 Apr. 
1905 ; no. 248). This form approaches a species of Tolypothri. 
338. CALOTHRIX Brauni, Born. $ Flah. 1. е. (1886) р. 368. 
Crass. fil. ad bas. 7-10 ш; crass. trich. 55-8 р. 
Tanganyika.—A mong Utricularia and other water-weeds in shallow water, 
mouth of Malagarasi River (16 Jan. 1905 ; no. 611). 
Forma filis ad basin subrectis. 
Crass. fil. ad Баз. 6-9 р; crass. trich. 4*5—6'4 д. 
Nyasa.—On rocks below level of water, Nkata Вау 
no. 23). 
(23 June, 1904 ; 
339. CALOTHRIX CARTILAGINEA, sp. п. (Pl. 10. fig. 7.) 
C. strato compacto late expanso, cartilagineo, atro-viridi vel sordide ærugi- 
noso, lignis vetustis affixo, 1 mm. crasso ; filis densissime confertis, curvato- 
flexuosis, imbricatis, plerumque curtis, ad basin leviter bulboso-inflatis ; 
vagina arcta et firma, hyalina, вере vix conspicua ; trichomatibus brevibus, 
in pilum brevem attenuatis, inter cellulas constrictis ; cellulis inferioribus 
diametro paullo brevioribus (rare triplo brevioribus disciformibus), plerumque 
torulosis, superioribus tam longis quam latis vel diametro usque duplo longi- 
oribus, cellula basali parva, cellula apicali subconica ; heterocystis nullis. 
Crass. fil. ad bas. 5-10 ш; crass. trich. ad bas. 45-94; hormogoneis toru- 
losis usque 50 p longis. ii 
Tanganyika.—Scraped from the inside of a canoe (6 Jan. 1905 ; no. 205). 
The trichomes of this species are rather short and somewhat variable in 
character. There are no heterocysts and the basal cell is generally consider- 
ably smaller than the cells just above it, a slight bulbous swelling being a 
general feature of the base of the trichome. The basal cells are shorter than 
their length, but in the upper parts of the trichome the cells are mostly longer 
than broad. In some of the trichomes each cell contains one or more promi- 
nent granules of large size, and occasionally in some of the thinner trichomes 
the basal region does not appear to be septate. 
