REPORT OF THE DIRECTOR I919 II3 



also occur in the Snake Hill and Canajoharie shales, though ranging 

 considerably higher up. 



We observed a continuation of this shale on the Vermont side of 

 the lake at Windmill Point in the town of Alburg, where in like hard 

 black calcareous shale the following species were obtained : 



Glossograptus quadrimucronatus (Hall) 

 Lasiograptus eudiaris (Hall) 

 Leptobolus insignis (Hall) 



How far south this horizon extends in the black shale belt of Ver- 

 mont we do not know, but suspect from some observations of ours 

 that it reaches the southern extremity of Grand Isle. 



One and one-half miles east of the outcrop at Windmill Point, 

 along the lake shore at Alburg, Vermont, there were found in alter- 

 nating black calcareous shale and black to dark gray impure lime- 

 stone, mapped with the Utica shale by the Vermont Survey, the fol- 

 lowing forms: 



Lingula (Palaeoglossa) trentonensis (Conrad) 



Lingula cf. curta Conrad r 



Dalmanella rogata Sardeson r 



Protozyga exigua (Hall) r 



Calymene senaria Conrad r 



Odontopleura trentonensis (Hall) r 



Primitiella unicornis Ulrich c 



Primitia sp. 



Ulrichia bivertex (Ulrich) r 



Tetradella subquadrans radiomarginata " Ruedemann cc 



Lepidocoleus cf. jamesi (H. & W.) 



The most common and characteristic fossils of this faunule are 

 Protozyga exigua, Primitiella unicornis 

 and Tetradella s ubquadrans radiomargi- 

 n a t a . These, in association with Lingula trentonen- 

 sis, Odoriitopleura trentonensis and U 1 r i c h i a 

 bivertex leave no doubt of the Trenton age of this dark calcare- 



' This variety has all the characters of the Trenton species Tetradella 

 subquadrans Ulrich, with the exception of the frill which bears dis- 

 tinct radiating lines, instead of being smooth, and is sharply bent up instead 

 of being concave. Two specimens measured 2.2 mm by i.i mm and 2.1 mm 

 by I.I mm, the variety thus having the exact dimensions of the tjT)ical 

 form. 



