in PALAEONTOLOGY OF NEW YORK. 



of the Lower surface impressions of the projecting edges of those tubules 

 are also visible. Between these openings may be seen minute pittings which 

 are the openings of .-mailer tubules. 



Dimensions. An average example affords the following measurements: 



Body. Cephalon. Thorax. Pygidium. 



Length 156 mm. 40 mm. 73 mm. 43 mm. 



Width 75 mm. 75 mm. 73 mm. 48 mm. 



The largest entire individual observed has a length of 220 mm. and a width 

 of 100 mm.; the smallest a length of 10 mm. and a width of 6 mm. 



Observations. Homalonotus Dekai/i, the latest and most prolific representative 

 of the genus in America, differs from the Homalonoti 'of the earlier Devonian 

 and the Silurian, both in this country and Europe, in the obsolescence of 

 the annulations of the pygidium at maturity. It is an abundant fossil in the 

 sandy shales of the Hamilton group of the central counties of the State where 

 it is usually preserved in the form of casts. West of Cayuga county it is of 

 much rarer occurrence and appears to be mostly confined to the shales above the 

 Encrinal limestone. In Genesee and Erie counties it is very seldom met with, 

 and in the eastern outcrops of this formation in Schoharie and Albany counties 

 it is not abundant. 



Distribution. Hamilton group. In the Marcellus shales on Flint Creek, 

 Ontario county: in the Hamilton shales at Bear's Gulf, near Summit, Schoharie 

 county : Cazenovia, Leonardville and Hamilton, Madison county ; East Worcester 

 and elsewhere, Otsego county : Pompey Centre, Pratt's Falls and Delphi, Onon- 

 daga county; Bellona, Yates county; Hopewell and West Bloomfield, Ontario 

 county; Tichenor's and Menteth's* Points, Canandaigua Lake; Darien, Genesee 

 county: Hamburgh and Eighteen-mile Creek, Erie county. 



■■■ -Thi.s name us used in the previous publications on the Palaeontology of New York, and a? spelled by the 

 original owner of the propertj on ( ianandaigua Lake, was Montt ill/. It is now understood that its present 

 owner lia-< changed the - pelling of the name to Mi nteth. 



