No. 2,] WHITEAVES — NEW DEVONIAN FOSSILS. 99 



pis have precisely similar head shields, but the body of Zenaspis 

 has a dorsal scute placed immediately behind the posterior 

 spine. In the absence of any knowledge of the body of the 

 Campbellton species, therefore, it is uncertain to which of these 

 two subgenera it should be referred. 



Including the C. Dawsoni of L:inkester, from Gaspe, all the 

 specimens of Cephalaspis hitherto described are said to be 

 characterized by a surface ornamented by raised tubercles, sa 

 that the C. CampheUtonensis may be readily distinguished by 

 its minutely pitted sculpture. In general outline the head shield 

 of the present species appears to be very much like that of the 

 Euceplialdspis Fowriei from the Old Red Sandstone of Forfar- 

 shire. 



Ctenacanthus latispinosus. Sp. Nov. 



Compare C. ornatus, Agassiz. Recherches sur les Poissons 

 Fossiles, Vol. 3, page 12, Table 2, figure 1. 



Fin spines small (as compared with those of most of the other 

 species of the genus) compressed laterally : either elongated, 

 slightly curved and tapering rapidly from a rather broad base to 

 an obtuse point, — or comparatively short, straight and triangular. 

 Posterior margin somewhat concave, and bearing on its upper 

 portion certainly one row and presumably two rows of shorty 

 conical booklets, which curve obliquely downwards. Anterior 

 margin thin, straight or gently convex, and unarmed. Surface 

 marked on each side by from 15 to 20 longitudinal ribs, which 

 swell out at regular intervals, of about one-third of a line apart, 

 into suDangular, equidistant nodes. 



Length of the largest spine collected, about two inches and a 

 half: maximum breadth of the same at the base, about three 

 quarters of an inch. 



The few spines of this species collected by Mr. Foord are all 

 partly imbedded in the matrix, so that the grooving of the poste" 

 rior margin is hidden from view, and only one row of booklets is 

 exposed. 



Homacaufhus. Sp. Undt. 



Compare H. arcuatas, Agassiz. Poissons fossiles du Yieux 

 Gr^s Rouge, page 113, Table 33, figures 1-3. 



Fin spine rather large (for a Homacanthus') compressed later- 

 ally, distinctly curved, slender, elongated and tapering very gra- 

 dually from a narrow base to an apparently obtuse point. Upper 



