characteristic feature of these sediments, in sharp contrast to the meni- 

 lite shales in which the Clupeidae are extremely coromon. 



Suborder Stomiatoidei 

 Family Gonostomidae 



Genus Idrissia Arambourg, 1954 



Idrissia carpathica n. sp. 

 (Figs. 3, 4; PL I, PI. V, Fig. 2) 



Diagnosis. 38 — 39 vertebrae (including 15 caudal), P* about 14, 

 V 6—8, D 10—11, A 13—14, C 10, 11—11, 10. Body narrow, head 

 large, jaws with sharply pointed conical teeth. Dorsal fin begins at the 

 middle of the body (without the caudal fin) or close by after it. Ven- 

 tral fins occur below the last rays of the dorsal fin. The anal fin is 

 placed 8 — 9 vertebrae behind the last ray of the dorsal fin. 



Material: 31 skeletons, including 19 complete or nearly complete, 

 the remainder more or less fragmentary. Some of the most completely 

 preserved specimens display more marked flattening and elongation 

 of the head and body, most likely due to diaigenetic processes. The 

 exact body dimensions could be determined only on measurements 

 taken of 8 most satisfactorily preserved specimens of various sizes, 

 (Nos. 28. Os., 42. Os., 45. Os., 46. Os., 73. Os., 77. Os., 164 Os., 187. Os.); 

 of these, 164, Os, was selected as the holotype, and Nos. 28, Os,, 45, Os., 

 77. Os, and 187, Os. as the paratypes. 



Table 1 specifies the dimensions of the holotype, the paratypes 

 and — for the sake of comparison — (after Arambourg, 1954) those of 

 Idrissia juhae Aramb., the only species thus far known from this genus. 



Description. These fishes are characterized by a rather narrow 

 body. The greatest depth fits 4.1 to 6.2 times (15.1 — 24.2 percent) 

 into the body length — without the caudal fin. In Idrissia carpathica, 

 the long head, characteristic of this genus, fits 2,9 to 3,2 times into the 

 body length — without the caudal fin. The orbital diameter exceeds 

 the preorbital area, with the exception of the case of a young specimen 

 (No, 42 Os.) in which these two values are almost the same. The diam- 

 eter of the orbit fits about 3 times into the head length, to the posterior 

 margin of the operculum. When comparing the head structure of I. juhae 

 Aramb. with that of I. carpathica n, sp, it is clearly seen that the preor- 

 bital area in the latter form is larger. 



Fins: P — pectoral, V — ventral, D — dorsal, A — anal, C — caudal. 



