76 R. R. GURLEY 
Climacograptus oligotheca Gurley, sp. nov. 
Polypary acutely isosceles-triangular, long and slender, widening very 
slowly; distal (‘‘proximal’’) extremity bearing two short lateral spines. 
Virgula stout, occupying about one-sixth width of polypary, greatly prolonged 
proximally and distally, the distal (‘‘ proximal’’) extension sometimes consist- 
ing merely of a short triangular process, sometimes of a virgular extension 
terminating in a vesicular dilatation, but generally forming a straight broadly 
filiform process which may be traced for some distance without evidence of 
termination. No vesicle or “disk” visible at end of proximal (‘distal’) 
prolongation. Length, 11°" or less; width about 2™". Ventral margins 
straight, interrupted by notches corresponding to the thecal mouths. Thecz 
1A (© WA iia BE, 
Horizon and locality.—Upper Dicellograpsus zone, Magog, Canada. 
This species is readily recognized by the proximal and distal extension of - 
the virgula, and by its straight parallel sides incised by a series of straight 
notches at comparatively distant intervals. It is most closely allied to C. 
antiguus, but is usually longer and has but 12 to 14 thece in 25™™", while C. 
antiguus has (by measurement on Lapworth’s figure) 20 in the same space. 
Climacograptus caelatus Lapworth, 1875. 
Quart. Jour. Geol. Soc. London, XXXI., p. 655, Plate XXXV., Fig. 8; 
not 2b., Lapworth, 1876 (see C. andiguus). 
The principal interest in our specimens attaches to the ‘“‘disk’’ which forms 
the proximal (‘distal’) termination of the virgula. This body is an obtrian- 
gulat-cordate leaflet, bilaterally symmetrical, and traversed medianly by the 
virgula. Some appearances suggest that it may possibly consist of two super- 
posed elliptic leaflets. It is sometimes at a distance from, sometimes close to, 
or in actual contact with the proximal (‘‘distal”’) end of the polypary. From 
the (apparent) dilatations of the virgula seen in LD. veszculosus Nich., D. 
palmeus (Barr.), and D. trifidus Gurley, it differs markedly in its distinct 
bilateral symmetry, and flat leaf-like appearance. This “disk” is present in 
a large proportion of the specimens. 
Horizon and locality.—Upper Calciferous, Summit, Nevada. Identified by 
Professor Lapworth from specimens sent him. 
Climacograptus kamptotheca Gurley, sp. nov. 
Polypary pretty uniformly 1™.5 broad and 35 to 4o™™ long; distally 
(‘‘ proximally”) tapering gradually for about length of last 7 or 8 thece to 
the narrow rounded extremity; maintaining its full width to the proximal 
(“distal”) extremity which is abruptly truncated. Virgula straight or 
slightly zigzagged, prolonged distally (‘proximally’) as a straight needle- 
like process, 2 or 3™ long; and proximally (“distally”) as a filiform exten- 
sion which in one specimen extends 12™™ without terminating in any “disk.” 
