THAXTER. 



MONOOKAI'H OK TIIK I, A B< ) I ' \M KX I A( ' K.K. 



253 



Imps possible that these three may l>c forms of one variable species, hut although I have found D. prin- 

 ceps on a variety of hosts from various parts of the world, and in abundance, I have never seen it asso- 

 ciated with I), dubius, unless it he on the above mentioned host. 1). vulgatux, as I have already men- 

 tioned, is also associated with a form like /). princeps which is, however, usually larger and stouter with 

 a tendency to black suffusions along the margins of the first tier (Plate XXXI, fig. 9), a tendency which, 

 though it may occur in D. dubius, is never seen in D. princeps. In the present species the fork-like up- 

 growths of the second tier are wholly absent, or rudimentary, and never colored; in striking contrast 

 to the normal condition in I). vulgattU3. Despite these various points of resemblance, a careful reexami- 

 nation of all the material has confirmed me in the opinion that the present species and probably the two 

 others above referred to, should be regarded as distinct from one another. As in other cases Peyrit- 

 achieUorlotvas, without auricles, are very frequently associated with this species. 



DlCHOMYCES HYBRIDUS Thaxtcr. Plate XXXI, figs. 15-1(1. 

 Proc. Am. Acad. Arts and Sci., Vol. XXXV, p. 423. April, 1900. 



Basal cell small hyaline with a red brown suffusion near the base: lower tier narrow and elongate, 

 opaque or sometimes with a median translucent line: middle tier rather narrow, not more than five of 

 the median cells distinguishable, and more or less conspicuously marked on the anterior side by dark 

 transverse flecks or stria;; distally hyaline or merely tinged with reddish brown above, becoming red- 

 brown and finally opaque below; the margins opaque, continuous with those of the first tier and extend- 

 ing upward to form fork-like opaque projections, as in D. furciferus, which equal or exceed the upper 

 tier in length; a single appendage arising posterior to the rather small purplish antheridium: upper 

 tier relatively large, distally concave, composed of from fifteen to thirty-three nearly hyaline cells with 

 reddish brown shades along the septa, the median cells sometimes flecked with reddish brown spots or 

 transverse stria? toward the base, bearing two to six perithecia which may be of two types associated 

 on the same individual or occurring on different individuals: the one type somewhat smaller, straighter 

 and more erect, reddish brown, the lower half often abruptly paler or nearly hyaline, tapering rather 

 abruptly to the tip, the lips of which are auriculate much as in D. furciferus; the other type larger, 

 rather characteristically divergent, tapering rather abruptly to the truncate unmodified apex; append- 

 ages hyaline, sometimes as long as or even longer than the perithecia. Spores 35 X 4 u. Perithecia 

 100-115 X 25-30 /i. Total length to tip of perithecium 250-300 fi. Receptacle 175-250 X 85-145 p.. 



With both types of perithecia (the type form): on Philonthus cencipennis Boh., Paris Museum, 

 No. 203, Gulf of Oman, India; on Philonthus sp., British Museum, No. 366, Sylhet, Assam, India; 

 Philonthus sp., Bengal, India, Berlin Museum, No. 825: P. Lewisius Shp., Japan, Sharp Coll., No. 1122; 

 on Philonthus sp., British Museum, No. 368, Hong Kong, China. 



With only one form of perithecium (not appendiculate) : on Philonthus ventralis Grav., British 

 Museum, Ealing, England; Paris, No. 207, Funchal, Madeira; British Museum, No. 426, Europe, 

 Berlin Museum, No. 823, Europe; Berlin Museum, No. 824, North America; on Philonthus sp., British 

 Museum, No. 495, Balthazar, Grenada, West Indies; British Museum, No. 369, China; on P. pro.ri- 

 mus Woll., British Museum, No. 403, Canaries; on P. gemellus Kr., British Museum, No. 367, Ceylon; 

 on Philonthus sp., Niagara Falls, N. Y. (C. Bullard); Fresh Pond, Cambridge. 



The type form of this species in which the ordinary perithecia may be associated with, or wholly 

 replaced by, a much shorter auriculate form, (figs. 16-17), has been found only on Asiatic material, and 

 it seems very doubtful whether the form common on P. ventralis and other species of Philonthus should 

 not be considered a distinct species. It is common on Philonthi about Fresh Pond, but neither in this 

 nor in any material not Asiatic have I seen the dimorphic forms. The ordinary non-asiatic type has not 

 been figured, but resembles that shown in fig. 15, perhaps somewhat smaller and more slender with usu- 

 ally longer and more slender "forks," and a more marked tendency to divergence in the perithecia, 

 which is commonly characteristic. A close comparison of the non-auriculate Asiatic type and the ordi- 



