TIIAXTKU. 



MONOGRAPH OF THE LABOULBKNIACK/TC. 



241 



on one side only, and consisting of from five to twelve cells. Perithecia one to five in number, the ap- 

 pendages from three to six, alternating with them, or succeeding one another somewhat irregularly; 

 the two series, perithecia and appendages, somewhat divergent; the subtending cells relatively large 

 and obliquely placed with reference to the bordering extension of the basal cell, so that they appear 

 larger from one side than from the other. Perithecium rather long and slender, nearly straight, stouter 

 and somewhat inflated in small individuals; the tip blunt or nearly truncate, tinged with smoky brown; 

 borne on a short inconspicuous stalk-cell from which it bends abruptly upward. Appendages rela- 

 tively large, consisting of two superposed cells, constricted at the septa; the basal one longer, distally more 

 deeply suffused; the upper distally suffused, and modified like the corresponding portion of the primary 

 appendage. Spores about 20 X 3 /«. Perithecia, in well developed individuals, 100 X IS ji. Primary 

 receptacle about 00 /i. Secondary receptacle (larger) 75 ji. Appendages about 58 X 13 fi. 



On Myrmedonia flavicornis Fauv., Brit. Mus. (Biologia C.) No. 70f>, Guatemala. 



This singular looking plant was found on various parts of the host, especially on the abdomen, and 

 shows considerable variation in the development of the secondary receptacle especially, small forms 

 occurring with a single perithecium only. The accompanying figures represent the most highly devel- 

 oped individuals, and show the tendency to degeneration which affects the tips of both primary and 

 secondary appendages. 



Dxmorphomyces Thleopor^e Thaxter. Plate XXVIII, figs. 12-13. 

 Proc. Am. Acad. Arts and Sci., Vol. XXXV, p. 410. Apr., 1900. 



Male inxlividual much as in D. muticus, the primary appendage ending in a short blackened cell, 

 bluntly rounded or nearly truncate. Total length to tip of antheridium 66 [j., to tip of sterile cell 37 ii. 



Female individual. Structure of the receptacle like that of the other species, but only developed 

 on one side of the median sterile portion, or primary appendage, which consists of three cells like that 

 of the male individual and is black tipped. The appendages and perithecia arising as in the other spe- 

 cies, the latter nearly symmetrically subfusiform, bluntly rounded at the tip, tinged with smoky brown, 

 the tip undifferentiated, the appendages relatively large and simple. Perithecia (not quite mature) 

 50 X 14 p.. Foot, to end of lateral portion, 50 (l. Total length to tip of perithecium 80 fi. 



On Thleopora corticalis Gz., Paris Museum, No. 297, Santa Anna, Madeira. On inferior surface 

 of abdomen. 



The material of this species is very scanty and it is impossible to determine the exact appearance 

 of the male individual, since a single specimen, only, is present in the preparations, placed as is shown 

 in fig. 12 at the right. The species is closely allied to the preceding, but differs in the form of the peri- 

 thecium, as well as in that of the primary and secondary appendages, the disorganization at the tips of 

 the latter causing them to appear truncate. 



DIMEROMYCES Thaxter. 



Eight additional forms of this very peculiar dioecious genus show that, although it is extremely well 

 defined in general, the species present remarkable variations in structure, and, with the exception of 

 Laboidbenia, inhabit more diverse hosts than the members of any other genus. With the exception of 

 Herpomyces, no other genus has been found on Orthoptera, and three East Indian forms occur on small 

 species of Diptera. Two of these dipterophilous forms, D. coarctatus and D. rhizophorus, which are very 

 closely allied, are of especial interest; since, although both occur on the integument of the inferior surface 

 of the abdomen of their soft bodied hosts, and thus live under practically identical conditions, the one 

 absorbs its nutriment by a well developed haustorium which penetrates the body-cavity, Plate XXVIII, 

 fig. 7, while the other, fig. 1, is attached by the usual foot and shows no sign of any penetration. It 

 is not improbable that the members of this genus will prove characteristic parasites on Forficulw generally, 

 as are the species of Herpomyces on Blattidae. 



