TRANSACTIONS OF SECTION K. 915 



Selaginellas agreed with the Lepidodendracese in possessing centrifugal primary 

 wood in the lower, and centripetal wood in their upper portions. The present 

 specimens possessing a solid protostele strengthens this comparison. 



4. On Bensonites fusiformis, sp. nov., a Fossil associated ivith Stauropteris 

 burntislandica, P. Bertrand, and on the Sporangia of the latter ^ Bv 

 Mrs. D. H. Scott, F.L.S. ' ' 



A description was given of some curious spindle-shaped bodies, first observed by 

 Miss Benson in petrified material from the Lower Carboniferous formation of 

 Burntisland. 



They are found in close association with Stauroptcris hi/rntislandica. The 

 author discussed their nature and inclined to the view that tbey are o-landular 

 structures belonging to the Sfaiiropteris. 



The sporangia of S. burntislandica were also described. One sporauo-ium was 

 found to contain germinating spores. 



This, with the two examples already described by Dr. Scott, makes the third 

 appearance of germinating spores amongst this group of plants. 



5. The Structure of Sigillaria scutellata, Brongn. 

 By E. A. Newell Arbrr, M.A., and Hugh H. Thomas, B.A. 



A full account of the structure of stems belonging to the Rhytidolepis 

 section of the EusigillaritB has not hitherto been given. In 1906, a grant from 

 the British Association enabled us to procure several beautiful specimens from 

 the Lower Coal Measures of Shore-Littleborough, in Lancashire. The character-; 

 of the ribs of one of them agree exactly with those of the impressions known as 

 Sigillaria scutellata, Brongn. 



The characteristic points in its structure are as follows : The stele has a 



medullary cavity, surrounded by a continuous ring of scalariform tracheides the 



primary wood. The outer margin of this ring is crenulated, and the protoxvlem 

 elements lie at the apices of the blunt, i-ounded teeth of the corona. ~ The 

 secondary xylem forms a band of radially arranged, scalariform tracheides. 



A well-developed band of phelloderm is found near the surface of the ribs. 

 This is regarded as having arisen on tlie inner side of a meristematic zone • no 

 definite cambial layer is, however, found. 



The ribs are really formed of cortical tissues, and not of fused leaf-bases. Thev 

 consist largely of phelloderm, and external to this there is a narrow zone of tissue 

 which is probably the primary cortex. The ribbing of the stem in the EusigillaritB 

 seems entirely independent of the form and arrangement of the leaf-bases. 



The presence of a ligule-pit and ligule has been detected for the first time in 

 petrified specimens. The course of the leaf-traces in the cortical tissues exhibits 

 interesting features. In the leaf-bases, the trace contains a double xvlem 

 strand, the two xylem groups being widely separated. The structure of the trace 

 is almost identical with the foliar bundle of the leaf described by Scott as 

 Sigillariopsis sulcata, which is obviously simply a leaf of a Eusigillarian stem. 



The parichnos increases greatly in size as we pass inwards from the exterior 

 of the stem. The two strands further unite, first below, then above the trace 

 so that at a deep level in the periderm the trace is completely surrounded by a 

 broad zone of this tissue. 



Published in extenso in Annals of Botany, October 1908. 



