[WILLIAMS] FOSSIL FAUNAS OF THE ST. HELEN'S BRECCIAS 227 



bear close resemblance to the species L. torta, Hall. The cross radiating 

 striae, however, are extremely fine and not as sharp as in the figure 5^ 

 representing that species. 



2. Fenestella sp. incert. 



A single specimen about an inch long and % inches wide shows 

 indistinctly the markings of a Fenestella frond but the preservation is 

 too imperfect for specific identification. 



3. Fragments of Crinoid stems are seen in the limestone, but 

 nothing by which to determine their generic or specific relations. 



The genus Or this is represented by a series of forms which may 

 be listed under the following names: Orthis (Dalmanella) cf. sub- 

 carinata, Hall; Orthis (Dalmanella) concinna, Hall; Orthis (Schizo- 

 phoria) muUistriata, Hall; Orthis (Rhipidomella) ohlaia, Hall. Good 

 representatives of these species are present. In the series, however, are 

 intermediate forms which arc not as easily distributed. 



4. Orthis {Dalmanella) cf. siihcarinata, Hall. 



There are five moderately convex specimens of pedicle valves 

 varying from 15 to 24 mm. in width which are referred to this species 

 by the slightly subcarinate form. The small specimens show tliis 

 cliaracter more strongly than the larger, but the distinctions separating 

 them froin 0. pereUgans are not well enough preserved to make certain 

 to which species they pertain. 



5. Orthis {Dalmanella) concinna, Hall. 



6. Orthis {Schizophoria) muUistriata, Hall. 



A series of specimens of gibbous dorsal valves, with finely striate 

 surface, show at their extremes (a) specimens with a decided " depres- 

 sion from beak to base " as in Orthis concinna; and (b) at the other 

 extreme those with evenly gibbous convex dorsal valves, as in 0. 

 (muUistriata. There are, however, still other specimens with surface 

 markings the same, but with slightly flattened central portion of tlie 

 shell. There are several small specimens, showing both valves, present- 

 ing the characters of Orthis muUistriata in both valves; also full grown 

 dorsal valves with the central portion of the shell raised as in 0. mul- 

 tistriata and among the latter those also showing the vascular marking 

 of 0. muUistriata. 



There is still another series of pedicle valves showing the flattening 

 of the front centre of that valve, and others with a slight depression 

 along the centre. In connection with these are almost as many which 

 present characters of surface-form intermediate between the extremes, 

 making it difficult to distribute them with either of the extreme types. 



1 Hall. J., Pal. N. Y., Vol. VI, 1SS7, PI. XV, Fig. 5. 



