432 



NEW YORK STATE MUSEUM 



Climacograptus modestus sp. nov. 



Plate 28, figure 30 



Description. Synrhabdosome not observed. Rhabdosome narrow 



(.7-1.4, in the majority of specimens i mm wide), but attaining considerable 



length (21 mm). Sicular extremity broadly rounded, rhabdosome attaining 



Y full width within the space of a few thecae and maintaining this to 



[ l antisicular extremity which is abruptly cut across without preceding 



■ t narrowing. Sicular extremity furnished with short virpfella and two 



Til J • • 



M \\ straight horizontal lateral spines. Sutural groove zigzagged with 



I 1 



,1 & 



Si 



4i«i 



401 



short, horizontal lateral branches. Sicula 

 1.5 mm long, slender. Thecae very closely 

 arranged, numbering 14 to 18 (mostly 16) 

 in the space of 10 mm, overlapping one 

 third of length, bent twice, two fifths of 

 length adhering to nemacaulus and directed 

 slightly inward, one fifth directed abruptly, 

 almost at right angles outward and last two 

 fifths subparallel to axis of rhabdosome or 

 slightly inclined inward. The distal free 

 part of theca squarish in compressed speci- 

 mens ; the apertural excavations in the lat- 

 ter are narrow horizontal notches, whose 

 depth is one fourth to one third of the 

 403 width of the rhabdosome. The septum 

 extends the whole length of the rhabdo- 



Fig.^a climacograptus modestus , sp . some andis apparently complete. Nema- 



nov. Different aspects of typical specimens. Sicu- 



lar end of specimen 400 not preserved ill as strong CaUlUS thill aild .sllOl't. 



relief as shaded. Figure 401 enlarged x 5, the others 



Formation and localities. This species 

 is very common in one of the layers of the Normanskill shale at Mi Moreno, 

 near Hudson, N. Y. and has also been observed in a few specimens in the 

 same horizon at the north vm\ of Lansingburg. 



Remarks. C. modestus is similar to C. parvus in some features 



