NEW DI.MORPHOMYCETEAE. 213 



acarine parasites approach Dimcromijccs in their characters, and it is 

 even possible that the two genera may have ultimately to be united. 



Of the remaining genera Xi/dcromyccs contains but a single species 

 on Strebla, X. Strrblidiuus, and is clearly distinguished by the possession 

 of a permanent bicellular receptacle in the female, and seriate lateral 

 antheridia in the male. The new genus Pulyandromyces, herewith 

 described, with one species and a variety on species of Coptosoma, is 

 unlike the others in possessing a single highly developed terminal 

 antheridiiun in the male, wliile the female approaches Dimeromyccs in 

 its structure. 



The species of Dimorphomyccs and Dimeromyccs hitherto described 

 are as follows: 



DiMORPHOMYCES. On Colcoptcra. D. Argcntinciisis Speg. (Z). 

 McroncvacTh.): D. denticidatusTh.: D. muticus Th.: D. Myrmcdoniae 

 Th. : D. Phdcnsis Speg.: D. Thicoporar Th.: D. Trogophloci Speg.: 

 D. vcrficalis Th. : D. vulgatissiiinis Speg. 



DiMEROMYCES. On Coleoptcra. D. Africauus Th.: D. Anla- 

 cophorac Th.: D. hrachiatusTh.: D. CoryuctisTh.: D. Hcrmocophctgae 

 Th.: D. Homo phoetae Th.: D. LongitarsiTh.: D. nanoviasculus Th.: 

 I). Pcichi Th. : D. pinnatus Th. 



On Orthoptera. D. Anisolabis Th.: D. appressus Th. : D. Forfi- 

 cukic Th. : D. Labiae Th. : D. vi i mdissim us Th.: D. Tha.xtcri Maire 

 (D. falcatus Th. nee Paoh). 



On Diptera. D. coarctatvsTh.: D. crispatusTh.: D . Kcimcruncnsis 

 Th.: D. Oscinosomal is Th.: D. pedcdis Th.: D. rhizophorus Th. 



On Acarini. D. falcatus Paoli: D. mucroruttus Paoli: D. muticus 

 Paoli. 



A possible addition to this list may be found in the Corcthromyccs 

 andicolus of Spegazzini, parasitic on Chiliotis, which is undoubtedly 

 either a species of Dimeromyces, or of Eudimeromyccs, the only 

 described species of which, from Chile, occurs on a host of the same 

 genus. The disorganization of the cells of the perithecium below 

 the ascogenic cell, clearly shown in Spegazzini's figui'e, is found only 

 in the Dimorphomyceteae and in Amorphomyccs among the unisexual 

 genera, never in Corethromyces. Spegazzini's Rickia Formicicola 

 may also prove to be a species of Dimorphomyccs, allied to the peculiar 

 types on mites herewith described; but the published figures are not 

 detailed enough to make a generic determination definite, in this case. 



A few other species of Dimeromyccs have been observed by the 

 writer, but are not here included, owing to the insufficiency of the 

 material, or for other reasons. As in previous instances, I am indebted 



