THAXTER. — LABOULBENIALES PARASITIC ON CHRYSOMELIDAE. 39 



its perithecium and receptacle. In the Mexican material the latter 

 is comparatively short and stout, while the former is much elongated ; 

 but in the Guatemala material the reverse is the case. What appears 

 to be an immature condition of the same species was also found on a 

 species of Luperodes from Porto Velho, Amazon, collected by Mr. 

 Mann, but none of the specimens have developed perithecia. The 

 hooked terminations of the branches in this form are somewhat dif- 

 ferent from the ordinary type. 



Laboulbenia Monocestae nov. sp. 



Receptacle relatively very small and compact, the basal cell usu- 

 ally quite hyaline, often curved, as large as the remainder of the re- 

 ceptacle combined; cell II and III + IV deep contrasting translu- 

 cent brown, the former very broad and short, obliquely separated 

 from cell I as well as from cells III + IV and VI; which is obliquely 

 placed, subtriangular, hyaline or partly suffused; cell III + IV mostly 

 suffused, broad and short, externally prominent; cell V very small, 

 triangular, its upper surface partly free between the base of the peri- 

 thecium and the insertion-cell. Basal cells of the perithecium hya- 

 line and contrasting, as are the lower external wall-cells of its main . 

 body; which is elongate, relatively very large, more or less curved 

 toward the appendages, dark rich brown, hardly inflated, tapering 

 very slightly at the broad apex; which is subtruncate or slightly 

 rounded; the lip-edges slightly suffused. Insertion-cell thick, nar- 

 row, opaque and indistinguishable from the externally blackened 

 basal cell of the outer appendage, which is variably developed through 

 proliferation that takes place distally from the inner side and results 

 in a variably developed crest-like series of from three to eight radially 

 placed branches, each usually once, less often twice branched, ex- 

 ternally blackened as are the outer branchlets, except distally; the 

 lower septa all suffused ; all the branchlets curved toward or past the 

 perithecium, rather stout, slightly, tapering: basal cell of the inner 

 appendage brown, erect, longer than broad, bearing distally a pair 

 of short branches usually consisting of a single cell terminated by a 

 pair of antheridia. Perithecia 85-125 X 25 fi. Receptacle 50-55 X 

 25-30 ix. Appendages, longest, 175 ju. Total length to tip of peri- 

 thecium 140-175 ijl. 



On the legs of Monocesta atricornis Ok., Manaos, Amazon, (Mann) 

 No. 2221. 



