T1IAXTKR. - MONOGRAPH OF TUK LA U( ) V LHKX I AC K.K. 



1 13 



to exist between the Exogenic and the Endogemc, from the fact that a discharge tube is developed and 

 that the sperm eells appear to he quite free at the moment of exit, not remaining attached or cohering 

 as they occasionally do in Ilhijnchopkoromyces. Although in Ccratorrn/cex and Aiitoiroiui/rcs the sperm 

 cells appear to be segments of actual branchlets, and in Zodiomyces they arise, if my former observa- 

 tions are correct, by exogenous budding as in the spermatia of many lichens, it is evident from these 

 intermediate conditions, that no hard and fast line can be drawn between the two types of origin. 



The species occur on water bugs, Corisidee, (often written Corixidae), and are the only forms known 

 to be parasitic on hemipterous insects. The discovery of this very interesting genus is due to Mr. 

 Charles Bulla rd who first observed it on Cofisee from the Cambridge region. 



Coreomyces ComS/E Thaxter. Plate LXXI, figs. 16-18. 

 Proc. Am. Acad. Arts and Sci., Vol. XXXVIII, p. 56. June, 1902. 



Curved or straight, pale dull brownish, nearly transparent. Cells of the receptacle distinguished 

 by more or less distinct constrictions, the three lower somewhat variable in length, the basal smaller, 

 usually tapering somewhat to the foot; the subbasal larger than either of the others, more or less inflated, 

 often as broad as the perithecium; the upper cell somewhat narrower, followed by the two to four, usually 

 flattened, appendiculate cells, which are successively longer, though usually slightly narrow from below 

 upward, the uppermost becoming about half as long as broad. The appendages long slender hyaline, 

 sparingly branched, slightly divergent; usually extending upward to, or considerably beyond, the tip of 

 the perithecium. Stalk-cell of the perithecium not differentiated from the cells below it, large, as broad 

 as the body of the perithecium above it, cylindrical or slightly inflated, about as long as broad or slightly 

 longer: body of the perithecium usually straight, somewhat darker dull brown, especially where it tapers 

 rather gradually to the small tip which becomes distinctly symmetrically four-papillate, and is usually 

 slightly bent to one side. Spores 85 X 6 fi. Perithecia 100-110 X 25-35 fi, the stalk-cell 30-33 X 

 32-35 fi. Receptacle, exclusive of the appendiculate cells, 75-100 ft. Appendages 200-250 /<. Total 

 length to tip of perithecium 275-290 p.. 



On inferior surface of abdomen of Corisa Kennicottii Uhler, Arlington (Bullard), on Corisa sp . , Iowa, 

 and on two species of the same genus collected near Fresh Pond, Cambridge. 



This species, which sometimes occurs in company with C. curvatus on the same individual, is always 

 found on the abdomen, usually near its extremity, on the under side. In a single instance a group of 

 individuals was found on the upper margin of one of the anal plates whieh differ in several respects from 

 the type form, having as many as seven appendiculate cells, a more elongate form and other slight differ- 

 ences which may prove of specific value. The material from Iowa corresponds in all respects with the 

 ordinary type found about Cambridge. The name of the host-genus is sometimes written Cori.ra. 



Coreomyces curvatus Thaxter. Plate LXXI, figs. 7-15. 

 Proc. Am. Acad. Arts and Sci., Vol. XLI, p. 318. July, 1905. 



Nearly hyaline, or but faintly tinged with brownish. Receptacle becoming narrow toward the small 

 basal cell, the two cells above the latter subequal in length, the appendiculate cells usually four, broader 

 than long, subequal or the lower shorter. Stalk-cell of the perithecium relatively long, slightly or not at 

 all inflated; the base of the perithecium often slightly inflated, the upper third or more bent abruptly 

 outward, tapering to the blunt curved apex, the concave side of which is edged with amber-brown, the 

 convex marked by slight indentations due to the prominence of the persistent wall-cells in this region. 

 Appendages as in L. Corisw, usually distinctly shorter. Spores 55 X 4 fi. Perithecium 130-140 X 36/z, 

 its stalk-cell 70 X 25 fi. Total length, average, about 350-360 fi. Appendages about 125 ft. 



On under side of margin of left elytron of two species of Corisa. Near Fresh Pond, Cambridge. 



Sufficient material of this form has been obtained on Corisa from an old clay pit near Fresh Pond, 

 to determine the constancy of its characters. Its occurrence on the left elytron appears to be invariable. 



