658 J. HOPKINSON AND C. LAPW0RTH ON THE GRAPTOLITES OF 



amples the proximal end of the polypary is usually broadly rounded, 

 and the primary processes, though invariably present, are rarely 

 very conspicuous. Some very long examples point in the direction 

 of the more recent varieties, the distal portions of the hydrothecse 

 being somewhat sacculate, and the denticles consequently more 

 rounded and projecting. 



Log. Lower and Middle Llandeilo, Abereiddy Bay. 



Diplograptus tricornis, Carruthers. PI. XXXY. figs. 6 a, 66. 



1855. Diplograpsus tricornis, Carruthers, Trans. E. Phys. Soc. Edin. 



p. 468, fig. 2. 

 1859. Grraptolithus marcidus, Hall, Pal. N". York, vol. iii. p. 514, 



figs. 1-3. 



Length from one inch to one inch and a quarter, with an average 

 diameter of one twelfth of an inch ; margins strictly parallel ; 

 proximal extremity abrupt, furnished with a well-marked 

 radicle and two similar diverging spines; virgula slender, 

 distally prolonged; hydrothecaB 25 to the inch, making an 

 exceedingly small angle with the general axis of the polypary ; 

 edge of aperture without distinct ornament, rarely projecting 

 outside the lateral margin. 

 The few specimens collected belong to a very diminutive variety 

 of this species ; and although they are in a fair state of preserva- 

 tion, the foregoing characters are all that can be satisfactorily made 

 out. The three distinctive proximal processes and the parallel and 

 slightly waved ventral margins of the polypary are well exhibited ; 

 and in some examples the margin of the thecal aperture is visible 

 as a short transverse line running partly across the periderm. The 

 virgula is always prolonged distally ; it is very slender, and affords 

 no evidence of ever having been furnished with that terminal fusi- 

 form appendage so frequent in some later varieties. 

 Log. Lower and Middle Llandeilo, Abereiddy Bay. 



Family PHYLLOGEAPTID^E, Lapworth. 

 Genus Phyllograptus, Hall. 



Phyllograpttts stella, Hopk., sp. nov. PI. XXXIV. fig. 6. 



Brit. Assoc. Report for 1872. 



General outline nearly circular, slightly wider than long ; radicle 

 minute, scarcely perceptible ; hydrothecaB about 40 to the inch, 

 very much curved, their angle of divergence from the general 

 axis increasing from about 20° to 80° from their origin to 

 their apertures ; apertures concave, strongly mucronate. 



This pretty little star-like species differs from all others of its 

 genus in its broadly circular form, and in the number of thecse in 

 the inch. We have found a single specimen only. Its length is 



