36 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 8o 



FAUNA OF THE HERMIT SHALE 



Genus BATRACHICHNUS Woodworth 



Batrachichnus Woodworth, J. B., Bull. Geol. Soc. Amer., Vol. ii, 1900, 

 p. 542, pi. 40, text fig. 2. 



This genus may be characterized as follows : 



Generic characters. — Small forms, quadrupedal, with four and five 

 toes on manus and pes respectively. With or without median groove. 

 Toes slender, radially arranged. 



Gcnotvpc. — BatracJiichuiis plainvillensis Woodworth. 



This genus contains two species from widely separated localities, 

 B. plainvillensis Woodworth from the Carboniferous of Massachu- 

 setts, and B. celcr (Matthew) from the Carboniferous of Nova 

 Scotia. The species Exocainpc ? delicafula Lull, a form of small size 

 with similar digital formula is ])rovisionally referred to this genus 

 to be known hereafter as B. delicatula (Lull). The digital formula 

 of Notalacerta jacksoncnsis Butts ' suggests its affinities also to be 

 with this genus to which it is now referred. Its 4 and 5 short, bluntly 

 rounded toes as contrasted with the five long and acuminate toes on 

 both manus and pes in the type species of Notalacerta (iV. inis- 

 souriensis) certainly justify its removal from that genus. It is, how- 

 ever, quite possible that a comparison of the type specimens might 

 show that B. jacksoncnsis and B. plainvillensis are cospecific. in which 

 event the latter would become a synonym of the former on the ground 

 of priority. This matter could only be settled satisfactorily by a 

 restudy and comparison of the type specimens, which is outside the 

 scope of the present study. 



BATRACHICHNUS DELICATULA (Lull) 



Plate 12 



Exocampe ? ■delicatula Lull. R. S., Amer. Journ. Sci., Vol. 45, 1918, pp. 544- 

 546, fig. 4, pi. 3, fig. I. 



Lull's original description, based on rather scanty materials from 

 these same deposits, follows : 



The smallest of the forms collected by Professor Schuchert consists of 

 a very delicately impressed fore- and hindfoot in relief on mud-cracked red 

 shale. The hindfoot is the larger and shows four slightly radiating digits, 

 but no trace of sole. The manus is also apparently four-toed with distinct 

 impressions of terminal claws. The digits radiate more widely, but here again 

 there is no palmar impression. The form may therefore be described as digiti- 

 grade. Faint indications which may represent phalangeal limitations may be 



'The Kansas City Scientist, Vol. 5, 1891, p. 18, text fig. 



