388 Transactions. — Botany. 



celled lateral branches. Tetraspores in tetrads. All the repro- 

 ductive organs come ofE close together from the same patch of 

 thallus. 



Hob. In the Bay of Islands (in June). 



I have seen no specimens of this. (R. M. L.) 



2. Ptilothamnion pectinatum, R. M. L. (? = Callithamnion pec- 

 tinatum, Mont., Prodr. Phyc, p. 9). Plate XXIV., figs. 1 and 2. 



Thallus minute, 3-6 mm. in length, and linear to linear- 

 lanceolate in outline, oppositely distichously pinnate and spar- 

 ingly bipinnated. Cells of rachis 30-50 /x in length and 15-25 ^ 

 in breadth. Pinnae at the base of the rachis generally simple, 

 from |-1 mm. in length, a pair springing from each cell. Towards 

 the middle, of the rachis they are sometimes compound. They 

 occasionally branch dichotomously, and are provided with a 

 pair of pinnules to each cell. The axils of pinnse and pin- 

 nules are about 45°-60' measurement. The pinnae consist of 

 about 20 cells, about 30-40 /^ in length and 10//. in breadth. 

 The pinnules are from |-| mm. in length, with similar cells to 

 those of the pinnae. The tetraspores are in tetrads, terminal, 

 and generally solitary at the ends of the pinnules ; however, 

 a second tetrasporangium is occasionally formed subsequently 

 to the discharge of the first. The cystocarps are also terminal 

 on the pinnules, the procarps being very similar to those 

 described by Heydrieh for Ptilothamnion schmitzii, and of very 

 simple character. In some cases a second cystocarp is appar- 

 ently formed close to the first, but I am not quite certain of 

 this, as my specimens are somewhat entangled and in bad con- 

 dition. The cystocarps apparently are readily detached, as I 

 have not yet found a mature one in the position of the procarp, 

 but they are always entangled among the pinna?. 



Distribution. — Auckland Islands (Montagne) ; Half - moon 

 Bay, Stewart Island (R. M. L., J. C. S.) : on a species of Cla- 

 dophora (? Cladophora colensoi). 



This is the first time this pretty little plant has been recorded 

 since the voyage of the "Astrolabe" and " Zelee " in 1841. 

 The identification is in the first place due to Agardh, to whom 

 I sent specimens. He apparently regarded it as undoubtedly 

 the same as Montagne's specimens, of which perhaps he may 

 have had a type. The description of Montagne's plant, which 

 may be given here for the sake of comparison, agrees well enough 

 with mine, except as to the tetraspores : " C. pectinatum (Mont.. 

 Prodr. Phyc. p. 9). Microscopicum, filo primario repente pin- 

 nato, pinnis pinnulisque oppositis patentibus, articulis evlindricis 

 diametro cluplo longioribus aut aequalibus : tetrachocarpiis axil- 

 laribus." 



