COPE ON ICHTHYIC FAUNA OF THE GREEN ElVER SHALES. 813 



Caudal peclnncle stoat. The vertebife are coutracted medially, and uot 

 shortened; they have two or three longitudinal keels, which are some- 

 wHat irregular in their connections. This species is larger than any of 

 the Erismatopteri yet known. 



Measurements. 



M, 



Leugtli from first dorsal spiue 0.073 



Length from first anal spiue '. 0.051 



Length of anal fiu '. 0.023 



Length of second dorsal spiue 0.015 



Length of third anal spine 0.013 



Depth at first anal spine 0.018 



ASINEOPS PAUCIRADIATUS, Cope, sp. nov. 



This Perch is represented by a single specimen, which is larger than 

 any of those of the A. squami/rons, which have yet been found, and which 

 is of more robust proportions. It differs materially in the radial and 

 vertebral formulae, and in the greater relative shortness of the dorsal 

 spines. I observe at the base of these a series of short subhorizontal 

 ba.silar interneural bones. 



Formulae :— Eadii : D. IX— 12; A. II. 7. Vertebrae : D. 9; C. 13. One 

 or two vertebrne may be concealed behind the epiclavicle, but these, as 

 in the description of A. sqnamifrons, are uncounted. The depth enters 

 the length 2.25 times, the caudal fin being omitted. The length of the 

 head is little less than the depth. The dorsal spines are not very ro- 

 bust, and are (excepting the first) of subequal length. The longest 

 equals only half the depth of the body at the middle of the second dor- 

 sal fin. The caudal is rounded, and the ventrals are below the pectorals. 

 The origin of the latter is a little in advance of that of the first dorsal 

 spine. Its base is attached to four short basilar bones, of which the 

 inferior two are stout in proportions. There are about ten rows of 

 cycloid scales below the vertebral column. Scales extend on the top of 

 the head as far as the orbits. The mouth is terminal. The total length- 

 of the type-specimen is 0'".243, of which the head constitutes 0"'.075. 

 The longest (uinth) dorsal spine measures 0"'.027, and the second anal 

 spine 0"'.02-J:. 



3II0PL0SUS AEBEEVIATUS, CopC, gCU. Ct sp. IIOV. 



Char. gen. — Allied to Lahrax and Perca. Branchiostegal rays, 7or S; 

 ventral rays, I. O.J scales ctenoid. Two dorsal fins slightly connected 

 at base; only two anal spines. Operculum rounded, without spiues or 

 emargiuatiou. Preoperculum without spine, and smooth on the posterior 

 border ; inferior border with teeth. Premaxillary and dentary with small 

 uniform teeth in a narrow series. Clavicle unarmed. Vertebra,* with 

 two lateral fossie. Caudal fiu emarginate. 



The discovery of this genus in the Green liiver Shales is of no small 

 importance to fossil ichthyology, proving the existence, at that early 



