with traces of the luminous organs. Hence, the greatest attention is 

 given in the present paper to anatomy and systematics. 



The lack of scales in the majority of remains — except those from 

 the genera Clupea L. and Equula Cuv. — is a characteristic feature 

 of the manner of preservation of fish remains from the Jaslo shales. 

 Only more or less distinct traces of scales are detectable in all the 

 other forms here considered, while detached Scales are extremely rare. 



The presence of some detached heads, belonging only to represent- 

 atives of the Clupeidae and Sternoptychdiae, may be of some interest. 



GEOLOGICAL CHARACTERISTICS OF THE JASLO 

 SHALES FROM SOBNIOW 



During recent years, the Jaslo shales — an important index hori- 

 zon in view of the extreme monotony of the Krosno beds — have 

 attracted the particular attention of many geologists (Swidzihski 1947), 

 (Jucha 1957,) (Jucha, Kotlarczyk 1959), (Koszarski, Zytko 1959). Within 

 the central Carpathians, these shales occupy varying positions above 

 the top of the menilite shales. According to Swidzinski (1947), the Ja- 

 slo shales occur as thin intercalations in the upper part of the middle 

 Krosno beds. 



At least two lithologically distinct horizons may be differentiated 

 within the Jaslo shales (Jucha, Kotlarczyk 1959), (Koszarski, Zytko 

 1959). The lower of the two is thicker and more widely distributed. 

 These horizons are composed of a varying number of layers of lime- 

 stone shales and limestones. The lower horizon is distinctly laminated, 

 while the upper is unlaminated. Koszarski and Zytko (1959) assume the 

 presence in the Jaslo shales of still another (median) horizon. The dis- 

 tance from the upper to the lower horizon of the Jaslo shales varies 

 from a score or so to above 100 m. 



The differentiation of the Jaslo shale horizons has so far been 

 based primarily on litho logical characters; some difficulty is therefore 

 encountered in defining their position in the horizontal section. Con- 

 sequently, an investigation of the ichthyofauna from these shales will 

 probably provide suggestions useful for the clarification of stratigraphic 

 problems. 



The fish remains here considered have been obtained from that 

 part of the Jaslo shales which Jucha and Kotlarczyk (1959) r'ecognized 

 as the lower horizon (former B horizon of Jucha, 1957). They were 

 collected in the village of Sobniow, about 3 km SE from Jaslo. The 

 position of these shales is shown in the geologic sketch map (Fig. 1; 



