872 



SGIENGE. 



[N. S. Vol. III. No. 76. 



upon whicli has been founded a distinct order 

 Bennettitese. This is not the place to go into a 

 full discussion of the important characters 

 which distinguish this form. They have been 

 fully considered by Carruthers, Solms-Laubach, 

 Saporta and Lignier. Mr. Seward sums them 

 up with characteristic conciseness and refers to 

 this genus six or seven distinct forms including 

 the B. Saxbyamis and B. Gibsonianus of Car- 

 ruthers. Solms-Laubach, it will be remem- 

 bered, confined the genus to the latter of these 

 species solely on the ground that the remark- 

 able trunk found on the Isle of Wight and so 

 fully illustrated by Carruthers is the only one 

 in which the included seeds are clearly shown. 

 The remaining species he preferred to place in 

 Buckland's old genus Cycadeoidea. Since the 

 publication of Lignier' s interesting researches 

 upon the structure of B. Morierei, the opinion 

 has gained recognition that there is a close re- 

 lationship between the genus Williamsonia and 

 Bennettites. Mr. Seward fully discusses this 

 in an extended introduction to a new species 

 collected by Mr. Eufford in the Fairlight clays 

 near Hastings, which he names Bennettites {Wil- 

 liamsonia) Carruthersi. This species is repre- 

 sented by no less than seventeen siDecimens, and 

 in addition to this there is a variety {latifolius) 

 of which some dozen specimens occur. These 

 all come under the head of Flores or floral 

 organs, which are carefully illustrated in two 

 plates and one text figure. Some of these 

 forms certainly resemble those referred to Wil- 

 liamsonia from the Potomac formation ; others, 

 it must be admitted, can scarcely be separated 

 from the specimens so fully illustrated by 

 Lignier, while still others seem to be sub- 

 stantially identical with those figured so long 

 ago by Young and Bird from the Yorkshire 

 Oolite and subsequently treated by Williamson 

 under the name of Zamia gigas. Carruthers re- 

 cognized the undesirability of referring such 

 forms to the genus Zamia, and therefore 

 founded the genus Williamsonia.* 



So far as known at the present writing, none 

 of the cycadean trunks of America reveal the 

 presence of the included fruits characteristic of 

 Bennettites Gibsonianus, but in all other impor- 



*See Science, N. S., Vol. II, No. 32, August 9, 

 1895, p. 147. 



tant respects these trunks resemble those which 

 Mr. Seward refers to this genus, and also all 

 those which Count Solms-Laubach would in- 

 clude under the name Cycadeoidea. So far as 

 their general appearance is concerned, both the 

 American and the Italian forms depart from the 

 original type of Buckland more widely than 

 from the Beuuettitean trunks of the Wealden. 

 The fact that Count Solms appears to have found 

 included anthers in the great Italian trunk Cyca- 

 deoidea etrusca seems to indicate that through- 

 out this great group of closely similar forms the 

 reproductive organs were the same, and that 

 the failure to find fully developed seeds in the 

 interior of most of these trunks is due to de- 

 fective preservation. It is not probable that 

 these seeds could long remain thus imbedded in 

 the cortex ; they must have possessed some 

 mode of extrusion, and it must have been a rare 

 accident that a trunk should be entombed at 

 the precise time when its mature seeds were 

 still included. This seems to have been the 

 case with B. Gibsonianus — a most happy acci- 

 dent for science. But in most other specimens, 

 and especially in many of the American, there 

 are indications within the floral axis of the re- 

 mains of former organs that have disappeared. 

 In some specimens these flowers closely I'e- 

 semble the one studied by Lignier, and the en- 

 veloping bracts are either still preserved or else 

 are indicated by definite cavities having the 

 same form. It therefore seems at least a reason- 

 able conclusion that most or all of the trunks 

 referred to Cycadeoidea by Solms-Laubach are 

 of practically the same nature as Bennettites 

 Gibsonianus. Further investigations now in 

 progress are likely to throw additional light 

 upon this subject. 



One other supposed cycadean trunk described 

 by Mr. ScAvard is of special interest because it 

 is that upon which was formally founded the 

 Dracsena Benstedi Koenig, which occurs so often 

 in the books. We have here at last the history 

 of this problematical form, first mentioned by 

 Mantell as having been discovered by Bensted 

 at Maidstone and supposed by him to be re- 

 lated to Yucca or Dracsena. Koenig, who was 

 keeper of the Mineralogical Department of the 

 British Museum where the specimens were, 

 seems to have labelled them by this name, and 



