104 TRANS. OF THE ACAD. OF SCIENCE. 



cording to Dr. Owen, the postero-lateral angles of the pygidi- 

 um are rounded, and not prolonged into sharp, slender spines. 

 Dr. Owen has given some excellent figures of the head and 

 pygidium of this species, in the work above cited, under the 

 generic title of Crepicephalus. This latter genus, as above 

 stated, appears to me to differ in no essential characters from 

 Conocephalites ; which has been extended by Barrande and 

 Angelin to include such genera as Solenopleura, JSryx, Cono- 

 coryphe, and Harpides. I have before me a specimen of 

 C. Wisconsensis from the Potsdam Sandstone of Lawrence 

 creek, near St. Croix river, Minnesota, which plainly exhibits 

 an ocular ridge on either cheek, extending obliquely forward 

 and inward from the eye to the glabella, and the facial su- 

 ture has likewise the same direction as in Conocephalites. 



Conocephalites Chippewaensis, Owen sp. 



' Lonchocephalus Chippewaensis, Owen, 1852. Geol. Rep. Iowa, Wisconsin and Minne- 

 sota, p. 676, Tab. 1, fig. 6 & 14, and Tab. 1 A, fig. 9. 



This species is much smaller than the preceding. The 

 glabella is rather strongly convex, conical, longer _ than 

 wide, strongly rounded in front, and with sides slightly 

 arched and converging very gradually from the apex pos- 

 teriorly. Some specimens exhibit two or three indistinct 

 furrows on either side, which are strongly curved back- 

 wards, while others show no traces of these furrows. The 

 dorsal furrows are linear, deep, and distinctly separate the 

 glabella from the cheeks and front. The neck furrow is 

 narrow and well marked. The neck segment is not as high 

 as the glabella, and terminates behind in a long slender spine. 

 In some examples the margin in front is emarginate, as shown 

 in two of Owen's figures (Tab. 1, fig. 6, and Tab. 1 A, fig. 9), 

 while in others it is gently rounded. We have a number of 

 specimens referable to this species, which may be regarded as 

 the type of the genus Lonchocephalus, proposed by the late 

 Dr. Owen. After a careful study of the examples before us, 

 some of which are from the localities cited by Owen, we are 

 led to the opinion that Lonchocephalus presents no features 

 of generic importance to distinguish it from Conocephalites ; 

 we therefore unite it with the latter genus, which has priority. 



The Conocephalites minutus of Bradley appears to be very 

 closely related to the species under consideration. 



Conocephalites hamulus, Owen sp. 



Lonchocephalus hamulus, Owen, 1852. Geol. Rep. Iowa, Wisconsin and Minnesota, p. 

 576, Tab. 1 A, fig. 12. 



This species appears to be quite distinct from the preced- 

 ing, but evidently belongs to the same genus. I have not 



