THAXTER. NEW LABOULBENIACEAE. 17 



externally and inferiorly to form a free buttress-like margin, much as in 

 H. Paranensis, which almost wholly covers the single fertile cell. Peri- 

 thecium yellowish, straight, nearly erect, the base bulging very slightly ; 

 but hardly broader than the ascigerous part, which is relatively large, 

 long, subcylindrical, or slightly inflated ; the distal part, relatively short, 

 rather abruptly distinguished ; the posterior cell row, which is external 

 in relation to the host, more prominent, with larger thick-walled cells, 

 the fifth from below prolonged to form a long, bluntly tipped, erect, 

 horn-like, subterminal projection, distally curved inward above the short 

 slightly incurved pointed subconical tip. Total length of peritliecium 

 (exclusive of base) to tip of process 150 /x; to tip 115 /x: ascigerous part 

 70-75 X 28-30 /x, distal part to tip 35-40 p. ; the process, free part, 

 25-30 /x, whole cell 40-44 /x. Secondary receptacles both together 

 55-65 X 25 /x. Total length to tip of process 175-185 /x. 



On Diploptera dityscoides Serv., Ascension Island, South Atlantic ; 

 Mus. Comp. Zool., No. 1371. 



Herpomyces tricuspidatus nov. sp. 



Male individual Yav'mhly developed, the terminal cell rounded apiculate, 

 but as a rule soon indistinguishable through proliferation, the simpler 

 forms very similar to well-developed individuals of H. Periplanetae, the 

 more complicated and most frequent type similar to the fertile branches 

 of the male individual in H. Ectobiae, producing, through continued 

 successive proliferation, a dense compact more or less appressed tuft of 

 antheridia which appear to be associated with undifferentiated sterile 

 branchlets. Antheridium long flask-shaped, hardly distinguished from 

 the usually several celled branchlet which it terminates. Total length 

 to tips of antheridia 75 ;x. 



Female individual. Primary receptacle small, surmounted by two 

 rounded cells constricted at the septa, the distal one bearing a small 

 sharp spine subtended by the usual minute blackish projection : the 

 subbasal cell producing apparently a single fertile branch which divides 

 at once, growing in opposite directions to form the somewhat irregular, 

 and variably developed, secondary receptacles, which may creep exten- 

 sively ; the component cells, which are often very numerous, being verti- 

 cally elongated and becoming arranged in two more or less complete 

 rows ; the inner mostly fertile, producing perithecia of which there may 

 be twelve or rarely more; the outer becoming several times closely 

 divided vertically, the cell-group which thus gives rise to the perithecial 

 stalk, laterally connected with corres[)onding adjacent cell-groups tiirough- 

 voL. xxxvm. — 2 



