286 



MR. H. HAMSHAW THOMAS 0]S' AX 



[vol. Ixxvii, 



Fig. 



2 . — D iacjra m in dica ting 



stalh (S), liead (H), and 

 iving (W). 



althougli there is no mention b}^ White of a part corresponding to 

 the wing. Other jDoints of comj^arison are also possible. 



The specimen now described exhibits some important distinctions 

 from the tj'-pe, as will be seen by comparing the figures ; it may, 

 however, be regarded as showing a different stage in the develop- 

 ment of the same organism, and, in the absence of a specimen 

 showing better preservation, I do not think that anything is to be 

 gained hj erecting a new genus for its reception. I propose only 

 to institute a new species, and shall therefore call the present 

 specimen Ottoharia Leslii, after its discoverer. 



Ottokaeia. 



Ottoeaeia Leslii, sp. nov. 



The original type consisted of a more or less circular lamina 

 seated on a long stalk, and the specimen now described shows an 

 ovate structure borne on a stalk. It is a little difficult to determine 

 the morjDhological nature of the parts, and to be at all certain of the 

 organs which gave rise to the impression here described. This is 



partly on account of somewhat 

 bad preservation, but more espe- 

 cially because of our ignorance 

 of any similarh^-shaped organ 

 in living plants. 



The fossil now described may 

 be termed an impression, but 

 the remains of part of the plant- 

 tissue are still left. Three 

 regions may be distinguished : — 

 (1) the stalk; (2) the thick- 

 ened circular portion or head, 

 Avith forking ribs of broAvn 

 cells; and (8) the thin apical 

 zone or w^ing. Tlie first and 

 second regions may be compared 

 in a general way with Zeiller's 

 Ottoharia ; but the third region 

 has no counterpart in the type- 

 specimen of the genus. 



Of the stalk only about 

 15 mm. is seen ; it has a uniform 

 Avidth of about 4 mm., and ex- 

 pands gradually into the head. 

 Most of the tissue appears to have become converted into a Avhite 

 structureless substance. In the centre of the stalk, hoAvcA^er, a 

 small streak of broAAaiish material is seen, and this may be compared 

 Avith the brown ridges to be mentioned later. It Avas probably 

 formed from the harder tissues of the A'ascular strand. 



The second region, Avhich may be designated by the non-committal 

 term of the head, sIioaa^s seA'^eral curious features. It is almost 



~w 



a---' 



b-,.. 



[a = scars of appendages ? ; 

 b=patelies of brown cells.] 



