THAXTER. — RICKIA AND TRENOMYCES. 371 



one or two of the uppermost bearinjij pointed antheridia: the append- 

 ages six to eight: the middle series of six flattened cells lying along the 

 inner margin of the perithecium for a little more than two thirds of 

 its length. Perithecium rather short and stout, slightly curved, 

 the apex blunt and opposite the bases of the flistal appendages of the 

 posterior series, the tip well distinguished externally. Spores 30 X 

 4/1. Perithecium 45 X ISyu- Free portion of the basal cell about 

 18 Ai; the rest of the plant 00-75 X 48-52 /x. Appendages 16-25 X 

 4 n, becoming brownish and subtended by the usual dark cup-like 

 base. 



On the inferior surface of a mite parasitic on Prioscelis sp. (?) and 

 belonging to a new genus near Cilliha. Kamerun, No. 2438. 



A species closely allied to R. Colcoptcrophagi Paoli and R. minuta 

 Paoli, differing in the form of its appendages and the arrangement of 

 its cell-series. The single type of R. Colcopterophagi as well as those 

 of R. minuta, are immature, so that it is not possible to judge of the 

 perithecial characters in these species. The latter, however, has been 

 received from Brazil (Mann) on various mites parasitic on Scara- 

 beidae, and an abundance of well matured individuals are available for 

 comparison. The species though very variable is quite well distin- 

 guished from the one above described. The tip of its perithecium is 

 wholly free; the cells of the middle series vary considerably in number 

 and extend as far as those of the posterior series, which is more nearly 

 vertical, the general habit of the plant being more slender; the basal 

 cell is not intruded between the lower cells of the anterior and pos- 

 terior series and there are other differences. 



Rickia pulchra nov. sp. 



Basal cell variably developed, more often short, the upper half 

 enclosed by the lower cells of the marginal series; or long and very 

 stout distally. Posterior marginal series consisting usually of four 

 cells, the lower opaque blackish brown bearing distally a very minute 

 rounded appendage, the next above somewhat rounded and cutting 

 off a small cell which subtends an antheridium, the third large tri- 

 angular, its pointed end directed upw^ard, and cutting off three to 

 five appendiculate cells which lie external to it; the uppermost small, 

 flattened, distally pointed, separating a single minute cell which lies 

 external to it and subtends a small short brownish spine-like append- 

 age: the anterior series consisting of three cells, similar to and sym- 

 metrical with the corresponding cells of the posterior series, and 



