202 MESOZOIC AND CAINOZOIC DINOFLAGELLATE CYSTS 



Dimensions. Holotype : overall length 56(1, breadth 45^, length of apical horn 

 iopi ; length of inner body 0.40(1, breadth 0.40(1.. Range of dimensions : overall 

 lengths 51-58^ 



Description. The holotype is enclosed in a roughly oval cloak of debris ; in the 

 three other specimens observed to date, the debris cloak was comparable. The 

 enclosing body is roughly lemon-shaped. The inner body fits quite closely, except at 

 the apical end where there is a quite large expansion of the pericoel. It is thin and 

 transparent and, as a result, very hard to distinguish ; its presence was confirmed 

 only under phase contrast. 



The debris cloak of the holotype contains a ball-like mass of debris immediately 

 posterior to the antapex. This structure is of doubtful significance and may simply 

 represent fortuitous adherence of organic debris from a quite unrelated source. 

 An archaeopyle has not been observed to date. 



Remarks. Paranetr elytron strongylum sp. nov. occurs in the 39 and 42-5 metres 

 horizons in the West Heslerton Borehole (Lower to Middle Barremian). Its small 

 size and debris cloak render it especially inconspicuous ; further studies may well 

 indicate a much wider distribution. 



Genus MUDERONGIA Cookson & Eisenack 1958 : 40 



Type species. M. mcwhaei Cookson & Eisenack 1958. Lower Cretaceous 

 (Aptian) ; Australia. 



(A ;A^ 



Fig. 52. Paranetr elytron strongylum sp. nov., showing the shell surrounded by 

 the enclosing cloak of organic matter. x c. 750. 



