486 MISS E. M. E, WOOD ON THE LOWER LUDLOW [May I9OO,. 



surfaces of rock with a delicate network of threads. In Bohemia I 

 have obtained it at a similar, and also at a slightly lower horizon. 

 At one locality it was associated with Monograptus Nilssoni and a 

 variety of M. colonus; at another it occurred together with Cyrto- 

 graptus Lundgreni, Monograptus testis, Metiolites nassa, etc. 



Foreign Localities. — Bohemia (Borek). 



British Localities. — Builth (River Irfon, etc.) ; Long Moun- 

 tain (Trefnant-Middletown Brook) ; Montgomery Road. 



Horizon . — Zone of M . Nilssoni. 



Associates. — M. Nilssoni, M. bohemieus, M. colonus, M. varians y 

 and M. dubius. 



Retiolites nassa. Holm (Gothograptus, Freeh). (PI. XXV T 

 fig. 30.) 



1890. Metiolites nassa, Holm, ' Gotlands Graptoliter ' Bihang till K. Svenska 

 Vet.-Akad. Handling, vol. xvi, pt. iv, no. 7, p. 25 & pi. ii, figs. 12-14. 



This characteristic little species has hitherto been obtained from 

 but one locality in Britain, and there only in a fragmentary con- 

 dition. The species has been so fully 



Fig. 27. Retiolites diagnosed by Holm and Wiman that a 



nassa, Holm ( x 5). complete description here is unnecessary. 

 It can be readily recognized by the following 

 jj^ characters : — 



(1) Polypary seldom exceeding 6 or 7 mm. 



(•025 to -03 inch) in length ; 



(2) Margin of polypary entire ; 



c|^3,, (3) Long initial canal present, terminating 



J£*<£| proximally in a spine ; and 



"ife- • (4) Thecal apertures resembling those of 



~\$&a Climacograptus. 



Foreign Localities. — Gotland - r 

 Bohemia (Borek). 



British Locality. — South side of the 

 Long Mountain, near Worthen. 



Horizon. — M.-vulgaris zone in Britain,, 

 Abroad it occurs in the highest zone of 

 [Enlargement of fig. 30 tne Wenlock, that of M. testis, and at the 

 in PL XXV.] base of the Lower Ludlow Beds in associa- 



tion with M. Nilssoni. 

 Associate. — M. vulgaris. 



In conclusion, I should like to express my sincere thanks to 

 Prof. Watts, M.A., Sec.G.S., for generously placing at my disposal 

 his collection of graptolites from the Long Mountain and his field- 

 maps of the country ; to Mr. Marr, F.R.S., for his kind permission 

 to examine his graptolites from the Lake District ; to my colleague 

 and friend, Miss G. L. Elles, in whose company much of my work 

 in the field was done, and with whom many points have been freely 



