THAXTER. — NEW LABODLBENIACEAE. 13 



in number, their points of contact with the host surrounded by a slightly- 

 blackened irregular foot-like haustorial margin, and giving rise to single 

 simple, or very rarely branched, haustoria which penetrate the wall of the 

 spine at right angles to its surface ; the cells all sterile with the exception 

 of the proximal one from which arises the solitary, nearly erect perithe- 

 cium. Perithecium relatively large, rather stout ; the ascigerous portion 

 large, slightly inflated, longer than the outwardly curved distal portion, 

 which tapers to the bluntly pointed unmodified apex ; the tip bent 

 abruptly outward. Spores 30-35 X 3 fx. Perithecia 125-185 X 35-48^. 

 Total length of primary individual 35-40 fx. Secondary receptacle 

 35-75 X 22 /x. 



On spines of legs, antennae and anal appendages of Periplaneta sp., 

 Zanzibar, Africa ,• Mus. Comp. Zool. On Periplaneta sp., Mauritius ; 

 Mus. Comp. Zool., No. 1357. 



Herpomyces Periplanetae nov. sp. 



Very variable according to the host and the position of growth. 



Male individual consisting of four superposed cells, the two upper, in 

 simpler individuals, producing one or two antheridia which are either 

 sessile or borne on a single stalk-cell : in more highly developed indi- 

 viduals the two distal cells producing short branches which may bear 

 several antheridia directly, or on secondary branchlets, some of which 

 appear to be occasionally sterile ; the total number of antheridia some- 

 times six or more. Greatest length of well-developed forms, to tips of 

 antheridia, 90 fx, of small specimens 60 /i. 



Female individual, hyaline or nearly so. Primary receptacle sur- 

 mounted by two or more sterile cells, the uppermost often asymmetrical, 

 ending in a terminal spinous process and bearing the minute character- 

 istic black projection laterally : the subbasal cell sometimes several times 

 divided, each resultant cell apparently giving rise to a single branch 

 from which is developed the very variable secondary receptacle. Sec- 

 ondary receptacle in simple individuals growing on spines of host ^ 

 consisting of a vertical series of from four to twenty or more obliquely 

 superposed cells, alternating to form a double row, otherwise similar 

 to that of //. chaetophilus and like it producing a single erect peri- 

 thecium from one of its uppermost cells : in individuals growing on the 

 integument of host ; consisting of a variable number of cells ; certain 

 fertile ones disposed subhorizontally on either side of the primary recep- 

 tacle, the fertile cells, of which there may be from one to six, together 

 with tlie male individual when present, and the bases of the perithecia, 



