TRAXSACTIOXS OF THE SECTIONS. 89 



led him, however, to take a somewhat different view of the numbers and characters 

 of the species ; and have enabled him to supply certain important omissions, and to 

 correct various minor errors of previous observers. He has been the first, it is 

 believed, to observe and describe the sperraogones and spermatia of the genus ; and 

 thus to give a complete account of its minute anatomy. The structure of the apo- 

 thecia appears to entitle this genus to be classed in the natural family of the Leci- 

 deacea. Tulasne desciibes the five following species : — 



1. Abrothallus Smithii. 



2. ,, Welwitzscliii. 



3. „ microspermus. 



4. „ oxysporus, 



5. „ inquinans. 



Dr. L. includes the three first species of Tulasne under his A. SniithV, retaining 

 Tulasne's specific characters as distinctive of varieties, which he denominates re- 

 spectively a. var. ater ; /3. var. pulverulentus ; and 6. var. microspermus. The fifth 

 species, which Tulasne himself designates a " species recedens," he discards as 

 not properly pertaining to the genus Abrothallus at all. The fourth he accepts as a 

 good and well-marked species. The species described by Tulasne and Dr. Lindsay 

 contrasted are therefore as follows : — 



1 J c -ij ■• T^ 1 -, rl. A. Smi I !ni, hinds. 



1 . yl. timithii, Tul. 1 . 



2. A. Welwitzschii, Tul. \ = \ "' " ,'"• , , 



o 1 • Til P pulverulentus, 



3. A. microspermus, lul. J "^ ^ . 



■^ L y. microspermus. 



4. A. oxysporu'), Tul. = 2. A. oxysporus, Linds. 



5. A. inquinans, Tul. omitted. 



The following are the full characters of the genus and its two species, as 

 emended by Dr. L. 



Genus. .467"0</iaZto, De Nrs. emend. Athalline : parasitic on the thallus of various 

 foliaceous lichens. Apothecia developed in medullary tissue of matrix : burst 

 through, sometimes fissuring in a radiate manner, the cortical laj'er, which may 

 form a raised border : finally seated on, or partially immersed in, the alien 

 thallus: at first flattened or discoid, sometimes becoming pulviniform or globose: 

 immarginate : circumference agglutinated to matrix or free : smooth or pulveru- 

 lent : mostly black. Thecal 8-spored: clavate, becoming obovate : amyloid 

 reaction with iodine often inconspicuous or absent. Paraphyses closely aggre- 

 gated : thickened, deeply coloured and cohering at their apices. Spores ovate- 

 oblong and obtuse at ends, or ellipsoid and acute : 2-locular, the loculi being 

 unequal in size and the larger one always looking towards the apex of the theca, 

 or simple : of an olive-green or brownish colour, or pale : frequently containing 

 two or more globular nuclei. Spermogones immersed, spherical, simple, open- 

 ing by a point-like or stellate-fissured ostiole : envelope of a deep brown tint. 

 Sterigmaia simple, slender, irregular, generating from their apices linear, straight, 

 slender spermatia. Pycnides also immersed, spherical, l-locular, opening by a 

 simple or stellate ostiole : generally larger and more conspicuous than the sper- 

 mogones. Sterigmaia short, simple, sometimes inconspicuous or absent : mo- 

 nospored : generating from their apices the stylospores, which are pyriform or 

 obovate, simple, pale, obtuse at ends, and contain an oily protoplasm or distinct 

 oil-globules. 



Species I, Abrothallus Smithii, Tul. emend, [including the A. Smithii, A. Wel- 

 witzschii, and A. microspermus of Tulasne ; and the A- Bertianus and A. Buel- 

 lianus of De Notaris and Massalongo.] Apothecia epithalline : scattered, 

 rarely confluent: prominent: pulviniform or globose: normally smooth and 

 black, sometimes green -pulverulent : circumference agglutinated or free: ulti- 

 mately falling out and leaving distinct, cyphelloid, variously coloured foveolEe, 

 which have sometimes raised and dark margins. Theca : amyloid reaction with 

 iodine feeble or none. Spores ovate-oblong : 2-locular, upper segment broader 

 and shorter than lower : olive-green or brownish : vary in size : locuh fie- 

 quentl)' containing one or two globular nuclei. 

 a. var. ater. Apothecia black and smooth. 

 [A. Smithii, Tul. in part.] 



