310 



MONOGRAPn OF THE LABOULBENIACE.E. 



uniform, but vary greatly in their numbers, being sometimes solitary or nearly so, as in Laboul- 

 benia Pachytelis, or produced in great numbers, as in L. Brachini and several others. Their 

 arrangement on the antheridial branchlets may be characteristic ; for while as a rule they are 

 apt to be solitary, in species like L. variabilis (Plate XXI, fig. 3), or L. proliferam (Plate XVII, 

 fig. 23), they are more or less definitely grouped. 



The homologies of the "receptacle" are evidently such as have, been previously described 

 (p. 206), the cells above cell II (Plate II. fig. 5) representing the union of the stalk-cells of the 

 perithecium (cells VI and VII; h and p of the figure), with the base of the appendage (cells III 

 to V), the latter (cell V) being, as may be seen when they have been separated by potash, in 

 reality a pair of cells placed side by side and appearing like one. The bodies spoken of as the 

 " appendages " in this genus are therefore morphologically only the branches of a main 

 appendage. 



With the few exceptions above mentioned, the type structure of the individuals which com- 

 pose the genus is remarkably constant and very clearly defined ; so that little difficulty will be 

 experienced in distinguishing it from all others. Its immediate connections with other genera 

 are not, however, clear, and its nearest ally is difficult to designate. 



The aquatic forms already enumerated might perhaps be separated in a genus by themselves, 

 were it not for the fact that their chief peculiarity, namely, the origin of their appendages, is 

 almost exactly paralleled by L. variabilis, which can by no possibility be excluded from Laboul- 

 benia. Unless other more important points of difference should appear, it is impossible thus to 

 separate them. It may, however, be remarked in passing that L. G-yrinidarum is one of the very 

 few species in which the character of the antheridia has not yet been satisfactorily made out, 

 although the trichogyne is highly developed. 



In the following descriptions the black cell from which the appendages arise is spoken of as 

 the " insertion-cell," the cells of the receptacle being numbered (I to VI), as in fig. 5, Plate 

 II, and the side bearing the perithecium is considered anterior. The species are sometimes cos- 

 mopolitan, and are very numerous and varied, inhabiting a great variety of hosts, including 

 Coleoptera, Diptera, Neuroptera and the Acarini. Many of the forms of what I have called the 

 " 'flagellata " type are very variable, and given species may inhabit hosts of many species and 

 even genera. Specific determinations are thus often difficult, and in the group of species repre- 

 sented by L. jiagellata, L. anceps, L. elongata, L. Peter ostichi, L. polgphaga, there is much uncer- 

 tainty in regard to the identities of many of the varieties. The synonymy in these cases is 

 also confused, and some names may have to be discarded. 



Laboulbenia Rougetji Mont, et Robin. 



Robin, Hist. Nat. d. Veg. Par. p. 622, Plate X, fig. 2 ; Montagne, Sylloge Cryptog. p. 250 ; Peyritsch Sitz. d. Wien. Acad. Vol. 



LXVIII, p. 247 ; Sorokin, Veg. Par. of Man and Anim. as a Cause of Contagious Diseases, Vol. II, p. 412, Plate 

 XXXIII, fig. 781 ; Winter, Die Pilze Deutsch. II, p. 921 ; Berlese Malpighia, Vol. Ill, p. 54 ; also in Saccardo, Syl- 

 loge Fung. Vol. VIII, p. 911 ; Thaxter, Proc. Am. Acad. Arts and Sci. Vol. XXIV, p. 12. See also Bon get, Produc- 

 tion Paras., etc. in Ann. d. 1. Soc. Entomol. d. France, 1850, T. VIII, p. 21, Plate I, figs. 1-7. 



" Dark yellow-brown ; Paraphyses inserted on a broad base, irregularly dichotomous, about 

 as long as the perithecium, yellow ; stalk much shorter than the perithecium." 



