MONOGRAPH OF THE LABOULBENIACE^E. 367 



the whole family, its spiral terminations being invariably present and of very regular form. 

 It is possible that the lower stalk-cell of the perithecium is morphologically a part of the 

 receptacle and not homologous with the ordinary stalk-cells. Its early derivation, however, has 

 not been determined. 



Compsomyces verticillatus Thaxter. Plate XI, figs. 6-15. 



Proc. Am. Acad. Arts and Sci. Vol. XXIX, p. 97 ; Cantharomyces verticillatus Thaxter 1. c. Vol. XXIV, p. 9. 



Nearly hyaline, becoming pale straw-yellow. Perithecium, very rarely more than one, not dis- 

 tinguished from its basal cells, inflated below, its slender, terminal portion tapering gradually 

 to the blunt symmetrical apex, the eight basal and sub-basal wall-cells producing a correspond- 

 ing number of more or less conspicuous prominences. Receptacle two-celled, the basal cell 

 sometimes furnished with a partly blackened outgrowth from its base. Appendages two or 

 three to eight or more, arising sub-verticillately from the sub-basal cell, simple or sparingly 

 branched, the cells short and usually distally expanded. Spores, 20-22 x 3 p. Pcrithccia, 90- 

 150 x 20-35 /jl ; its two stalk-cells (longest), 185 Receptacle, 18-80 p. Total length to tip 

 of perithecium, 140-400 /x. 



On Sunius longiusculus Mann., Anna, Illinois and Kittery Point, Maine. 



This graceful form was first received from Prof. S. A. Forbes, who kindly sent me two 

 mounted specimens from Illinois, on which the original description was based. These speci- 

 mens, however, were so imperfect that its really essential characters (the form and position of 

 the antheridia) were not made out. Its general structure, however, seemed so like that of Can- 

 tharomyces Bledii, received at the same time from the same source, that the two were united 

 under a common generic name. Later, more abundant material of C. Bledii and the discovery 

 of two additional species offered an opportunity for a more exact characterization of the genus 

 Cantharomyces on a basis of these three species, the C. verticillatus of my first paper being 

 still in doubt until an abundance of material was obtained at Kittery. 



The species varies very considerably in size according to its position on the host, specimens 

 on the elytra and near the tips of the legs being often very small. The length of the recep- 

 tacle also varies very considerably, and the hoof-like modification of the foot (fig. 13), which 

 finds a parallel only in Laboidbenia Philonthi (Plate XXII, fig. 28) sometimes occurs. The 

 rounded projections from the lower cells of the perithecial wall (fig. 11), are also very variable 

 in form and are often hardly apparent. In very rare cases the lower stalk-cell of the perithe- 

 cium may bear two appendages from its distal end, which though almost invariably simple, 

 may sometimes produce short branches. Two perithecia (fig. 8) have been observed in only two 

 instances. The antheridia (fig. 14) are produced in small numbers, one or two from the distal 

 ends of some of the lower cells of the appendages. 



The hosts are common in dry rubbish in cultivated fields. 



