/12 2 NEW YORK STATE MUSEUM 



Non Climacograptus scalar is Walcott. Geol. Soc. Am. Bui. 1890. 



i: 339 

 Non Climacograptus scalaris Ami. Can. Geol. Sur. Rep't. Ser. 2. 

 1889. v. 3, pt 2, P.117K 



Description. Synrhabdosome not observed. Rhabdosome small (10-14 

 mm long and 1.1 mm wide), with parallel sides and broadly elliptical section. 

 Sicular and antisicular extremities rounded. Lateral faces possessing 

 slightly undulating median sutures (complete septum). Virgella and free 

 nemacaulus not observed. Sicula small, slender, a little more than 1 mm 

 long. Thecae numbering 10 to 12 in the space of 10 mm; twice bent. 



first parallel to axis of rhabdosome (first third), then 

 obliquely upward at angle of 30" (second third) and 

 finally again into parallelism to axis of rhabdosome 

 in distal third. Apertural margin oblique, or slightly 

 everted ; apertural excavations triangular notches (one 



C ) fourth of length and one fourth of width of rhabdosome ). 



3Ss 386 387 Position and localities. Numerous specimens were 



Fig. 385-87 Climacograp- 



tus scaiaHs var. annuia- f OU nd in a boulder of ferruginous sandstone, probablv 



tus nov. Fig. 385, 386 Iwo & ' JT J 



views of type specimen, (x 5). r ^-,.. , , , . ■» T .^.1 r -~. ■»- 1 , 



Fi K . 387. Frontal view of thecae of Clinton age, collected by Mr (Jlot U. JNylander. 



and cross-section of rhabdosome. o > • 



<X7) of Caribou, Me. at Aroostook, Me. No associated 



fossils were observed. 1 



This species, which hitherto has not been found in North America, has 

 the distinction of being one of the longest known and most widely distrib- 

 uted graptolites. In Europe it is especially well known from Scandinavia, 

 where it occurs in Scania in the last zone of the Champlainic (Ordovicic) 

 which according to Lapworth is already a basal zone of the Siluric, is especi- 

 ally common in the higher horizons of the lower Siluric (Rastrites shale) 

 and is the index form of the C. scalaris shale. Tornquist records it from 

 the first zone of the Scanian Rastrites beds (/one of Diplogr. acuminatus) 

 and the third and fourth zones, in the latter of which it is the most common 



' Mr Ny lander writes that the boulder apparently comes from the sandstone belt west 



of tin-- Aroostook limestone and the Chapman sandstone. 



