THAXTER. — RICKIA AM) TRENOMYCES. 381 



which loaves the external margin of the peritheeiuin wholly free as in 

 R. Celacnopsis. There appear to be two cells in the anterior series, 

 the upper of which is almost concealed hy the base of the perithecium. 

 I have seen no indication of an anthcridium in either of the three 

 specimens from which the description has been drawn. 



Rickia filifera nov. sp. 



Small and slender. Basal cell obliquely separated from the lower 

 cell of the anterior marginal series which consists of two subequal 

 cells; the upper extending a short distance upward external to the 

 base of the perithecium: posterior series consisting of a variable 

 number of cells (eight to fifteen) the basal extending above the base 

 of the perithecium, the subbasal lying opposite to it; the third extend- 

 ing beyond its tip; the rest superposed to form a long, slender, erect, 

 or slightly outcurved appendage, terminated by the undifferentiated 

 basal cell of the primary appendage: the basal cell of the series, and 

 many of the others, cutting off a small appendiculate cell distally and 

 externally: median series consisting of two cells, the lower lying 

 opposite the upper half or less of the perithecium, the upper in contact 

 wnth the third and fourth cells of the posterior marginal series, its 

 inner margin wholly free. Perithecium slender, the tip well dis- 

 tinguished externally and bent slightly outward, the inner lip-cell 

 forming a short projection. iVppendages slender, cylindrical, hyaline, 

 10 X 2 M. Spores 24 X 2.5 fx. Perithecia 35-45 X 8-12 fx. Basal 

 cell including foot 12 X 4-5 m- Total length to tip of perithecium 

 35-45 X 8-12 fx. Longest free flagellum, including primary append- 

 age, 175 /i. 



On a very large mite allied to Mcgisthanus, on Passali. Kamerun, 

 No. 2442. 



This species varies considerably in size and in the length of the 

 extension of its posterior marginal row. No antheridia have been 

 recognized, although material of various ages is available. It is 

 perhaps most nearly related to R. Mcgisthani but resembles it only 

 remotely, and cannot be confused with it on account of its free " flagel- 

 lum." 



Trenomyces. 



This very curious genus was first discovered by Chatton in France 

 on Mallophaga infesting domestic fowls, and had been received by me 

 from Dr. jMiiller who collected it at Elbing, Prussia, and from Dr. 



