THE LICHEN-FLORA OF CHICAGO AND VICINITY. 41 



Verrucaria, (Pers.) Tuckerm. Thallus crustaceous, sub-tartareous, 

 mostly uniform ; apothecia globular, black, immersed or 

 prominent; perithecium black. The synonomy of this genus is 

 numerous. Tuck. Gen. Lich. 263. Verrucaria is restricted 

 here to the rock and earth lichens, species taken from Pyrenula 

 and other genera, which, as Tuckerman remarks, shows a 

 full and harmonious spore-character. In Europe a large 

 number of forms have been included under Verrucaria, but 

 Fries and Nylander have made a great reduction. 



115. V. pfospefsella,* Nyl. Spec. nova. Thallus uninterruptedly white 

 or scattered, becoming chinky with age reaction; apothecia 

 pyrenoid, wholly black, small (breadth, .15 mm.), some- 

 what globose, rather prominent. Spores 8. colorless, 

 oviform, i septate, .018-22 by .008-. on mm. The para- 

 physes few or scarcely any. Hymenia gelatinous-reaction. 

 Occurs on siliceous rocks near Chicago, (Calkins). This spe- 

 cies- seems to approach V. inconspicuam, Lahm, from which 

 it differs by its larger spores. Likewise near to V. saxicola, 

 Mass. The calcicolous species, V. ruderella, Nyl. also occurs 

 in the same locality. Nyl. Chall. p. 217. 



First found at Riverside. Described and published by Dr 

 Nylander in his "Obs." Lichens Japoniae, Paris, 1890 

 Abundant so far as known. 



116. V, pyrenophora, (Ach.) Nyl. Thallus tartareous, chinky, ash- 

 colored or continuous and rugulose; apothecia prominent, 

 black, large conoidal, sessile; perithecium dimidiate. Spores 

 8, colorless. Ach. L. U. 285. (I8IO). 



On rocks at Riverside, Lemont and throught our territory. 



117. V. nigrescens* Pers. Thallus nearly black, crustaceous, 

 uneven, crumbling, and often raised around the apothecia; 

 apothecia black; perithecium dimidiate. Spores 8, colorless. 

 On limestone along streams in various localities. 



*V. rrospersella, Nyl, Spec, nova, Thallus albidus continus, vel passim obso- 

 lete rimulosus; apothecia pyx-enio iiitegie nigro, mlauta (latit. 0,15 miliira.), subglo- 

 bulose prominiila: sporae 8 nae Incolores oviformes l-septatfp., long. 0.018-22, crass. 

 0,008-011 millim: paraphyses graoiles parciB vel vix ullse. Gel. hym. I. Super saxum 

 siliceum baud prooal a Chicago (Calkins). Accedere videtur ad V. inconspicuam, Lahm. 

 a qua mox differt sporis majorihus. C. fr. etiam V. saxicola, Mass.--Calcicola ibidem 

 (idem) V. ruderella, Nyl. Chall. p. 217. 



