178 PROCEEDINGS OP THE AMERICAN ACADEM5T 



ceeding the tip of the receptacle. Spores 55 x 4 p. Perithecium 

 150-165 X 45-55 ii. Receptacle, main body about 75 X 30 it, its 

 prolongation about 35-40 ft. Stalk of perithecium about 40 X 30 /*. 

 Appendages (longest) 375-500 p. 



On abdomen of Lathrobium fulvipenne Grav., Germany. 



A small species, distinguished by its short receptacle and elongate 

 appendages. As in A. furcatus, the receptacle may continue to grow, 

 producing in a similar fashion one or even two additional perithecia. 

 This phenomenon, however, seems in both cases to be usually associ- 

 ated with non-fertilization of the trichogynes, or with accidental injury 

 to the perithecia first formed. 



ACANTHOMYCES LATHROBII, nOV. Sp. 



Perithecium becoming slightly suffused with brown, its conical tip 

 dark brown, contrasting; rather slender, slightly inflated towards the 

 base, borne on a short stalk cell more or less concealed. Receptacle 

 consisting usually of eight to ten superposed cells, forming the main 

 axis and deeply suffused with blackish brown except at the nearly hya- 

 line septa. Appendages large, curved, almost opaque, nearly equal- 

 ling, often greatly exceeding the tip of the perithecium. Spores about 

 50 X 4 fj.. Perithecia 100-130 X 35-40 it. Appendages (longer) 

 150-450 it. Receptacle (average) 110 ii long. 



On abdomen of Lathrobium longiusculum Grav., New Hampshire 

 and Lake Superior ; Lathrobium sp., Pennsylvania. 



The appendages of the specimens from New Hampshire are con- 

 stantly far longer than those of the Lake Superior specimens, resem- 

 bling A. brevipes in this respect. The two forms seem otherwise 

 identical, and are distinguished from A. brevipes by the characteristi- 

 cally brown-tipped perithecium, longer receptacle, and more densely 

 crowded appendages. 



CHjETOMYCES, nov. gen. 



Receptacle slender, consisting of numerous superposed cells, from 

 which arise successively the appendages and one or more perithecia 

 in a unilateral series. Perithecium flattened, the symmetrical apex 

 prominent, borne on two stalk cells surmounted by several basal cells. 

 Fertile appendages arising from cells of the receptacle immediately 

 below the perithecium; sterile appendages arising from its terminal 

 cells. Spores as in other genera. 



