188 THE JOURNAL OF BOTANY 



described by Saccardo, but there is no true pycnidium. There is 

 merely a blackened layer of altered epidermis, lying above the 

 proligerous stratum on ^vhich the Phoina-like spores are produced. 

 This can be traced, on other parts of the same stem, into a stroma 

 which covers a rather dense sclerotioid mass of colourless cells, 

 and finally into the ordinary perithecia-bearing stroma of the 

 Diaporthe. The so-called Phoma is in fact hardly distinguishable 

 from a Leptothyrkim. Among the spores were seen a small 

 number of the peculiar uncinate sporophores which are considered 

 a distinguishing mark of the subgenus Pliomopsis. These looked 

 exactly hke the " walking-stick" spores of some species of Phlyc- 

 tcena. (Tab. 542, fig. 5.) 



In view of the disputed question whether these really are 

 sporophores or another kind of spore, a careful investigation was 

 made of the hymenium of this species. The prohgerous stratum 

 is composed of a mass of small olivaceous cells ; the erect colour- 

 less cells which constitute the hymenium vary greatly in shape 

 and size, but can be arranged in a gradual series, beginning with 

 those which are merely oblong, passing on to ampulliform cells 

 with a flask-shaped base and an acute apex, then into longer 

 lanceolate cells on the apex of which a young spore is borne ; 

 these finally become acicular, and in that stage the spore has 

 usually been cast off. No filiform or hooked structures were seen 

 in situ, only loose among the spore-mass, but since these agreed 

 in size with the acicular sporophores and some of them still had 

 one end shghtly thicker than the other, the conclusion seemed to 

 be inevitable that they constituted the final stage in the develop- 

 ment of the sporophores, but that they did not assume the 

 uncinate-filiform appearance until they had been cast loose from 

 the hymenium, after losing their spores. Nevertheless, filiform 

 spores (which became hooked when free) were seen in situ in 

 Phoma lirelliformis (see preceding species), which is probably 

 also a Pliomopsis. 



221. Phoma stei^formis var. hysteriola Sacc. Syll. iii, 132. 

 Pycnidia immersed, erumpent by a slit in an hysterioid 



manner, forming linear black streaks parallel to the striae of the 

 stem. Spores lanceolate-oblong, acute at one end, 6-8 x 2|-3 ju, 

 biguttulate ; sporophores long, acicular. 



On stem of ClicBrophijllmn temulwn, Storeton, Cheshire (J. W. 

 Ellis), March. The specimens which I attribute, somewhat doubt- 

 fully, to this variety have exactly the appearance of a Pliomopsis 

 such as that just described ; there is no true pycnidium, but 

 merely the altered epidermis, and the spores are borne on sporo- 

 phores longer than themselves, as in that species. 



222. Phoma iridina Maire & Sacc. Syll. xvi, 1154. 

 Pycnidia scattered, oblong or lanceolate, immersed, at length 



erumpent, convex, black, up to J mm. long, surrounded at the base 

 by a few brown hypha? ; texture parencliymatous, dark-brown. 

 Spores oblong-fusoid, subacute at both ends, especially below, 

 7-9 X 2-2i /x. 



