670 THAXTER. 



slightly oblique, bearing no antheridia; the subbasal usually five 

 sided, but slightly longer than broad, bearing a single antheridium 

 on the inner side; the third and fourth subtriangular, flattened, the 

 latter often slightly larger, each bearing a single antheridium; the 

 series of three superposed, their curved necks turned toward the 

 perithecium, and terminated by a fourth which is conspicuously spi- 

 nose on its inner side just below the middle. Inner basal cell of the 

 perithecium more than twice as long as broad, extending somcAvhat 

 lower than the slightly stouter and shorter outer cells which lie parallel 

 to it, all faintly yellowish: venter of the perithecium more distinctly 

 suffused, of nearly the same diameter throughout, or slightly inflated, 

 about as long as the distal portion; the wall-cell becoming distin- 

 guished at maturity by usually inconspicuous ridges, which acquire a 

 spiral twist, making about a quarter turn, and each ending in a slight 

 prominence below the rather abruptly distinguished neck, which 

 tapers slightly : the tip clearly, but not very abruptly distinguished, 

 slightly more than twice as long as broad, distally somewhat inflated, 

 or even geniculate below the short rounded slightly inflated apex; the 

 lip-cells hardly, or but slightly prominent. Spores 36 X 4.5 fx. Peri- 

 thecia above basal cells, 185-200 X 30-35 iji, maximum 250 X 40 /x: 

 the basal cell region 30-40 X 26-28 ijl. Receptacle 70 X 25 fx, maxi- 

 mum 150 X 28 ju. Total length 325-400 fx, maximum 410 /x: to base 

 of appendage 125-140 X 38 m; maximum 235 X 38 /x. Appendage 

 65-75 X 10 ^t, maximum 85 /jl. 



On the abdomen and legs of Xotiphila spp., No. 1859 (Type), 

 Balaclava Jamaica: Xos. 2808-2809, St. George, Grenada, W. I. 



A species very clearly distinguished by its peculiar appendage, and 

 the arrangement of its cells above the receptacle. It usually grows in 

 tufts on the legs, but the shorter and more compact form, which is 

 found on the abdomen, has been taken as the typical one. The species 

 varies but slightly, except that individuals growing on the legs may 

 be very much elongated. The four ridges which separate the wall- 

 cells of the venter, are not at first distinguishable, but become more 

 prominent as individuals become full}' mature. 



Of the forms which are parasitic on species of ParaJivrna, P. ciliaia 

 and P. decipiens, a large series has been examined, and it has proved 

 very difficult satisfactorily to determine their specific limitations. 

 The two forms which I have called S. Jamaicensis and S. curvirostris 

 seem well defined, owing to the character of the appendage, as well 

 as to their general form. Among the others, however, such numerous 

 variations appear to exist, that I have even hesitated to separate 



