Mr. C. Lap worth on new British Grdptolites. 149 



XIV. — On new British Oraptolites. 

 By Charles Lap worth, F.G.S. &c. 



[Plates IV. & V.] 



Within the last few years many new forms of British Grap- 

 tolites have been added to my collection. In the present 

 paper [ propose to give brief diagnoses of such of these unde- 

 scribed forms as I find it necessary to refer to in the conclu- 

 ding portion of my memoir on the Geological Distribution of 

 the Rhabdophora*. At the same time it will be advisable to 

 make such notes and observations upon the less perfectly 

 understood species among those already described by paleon- 

 tologists as may serve to bring our knowledge of these 

 forms up to date. Such species as have mainly a classifica- 

 tory or zoological value will be here passed over. Those 

 forms alone will be noticed which are of interest from a strati- 

 graphical or geological point of view — as indices of recog- 

 nizable horizons in the vertical series of rock-formations, or 

 as being remarkable for their extended geographical distri- 

 bution. 



The majority of the forms under review are from my own 

 collection. One was sent me by Dr. Callaway several years 

 ago. Two were collected by Mr. John Hopkinson, F.G.S., 

 in the Lower Ludlow rocks of Siluria, in 1873, and were 

 named by him at the same timet, but have hitherto remained 

 unfigured and undescribed. The remaining species have been 

 collected by myself at various times from the Lower Palaeozoic 

 rocks of Scotland, the Lake District, Wales, and the west of 

 England. 



Family Monograptidae. 



1 . Monograptus leintwardinetisis, Hopk. MS. 

 (PI. IV. figs. la-Id.) 



Monof/raptus leintwardinensi$, Hopkinson, Geological Magazine, 1873, 

 p. 520, 1875, p. 561. 



Polypary short and stout, never exceeding half an inch in 

 length, with a maximum diameter of one twelfth of an inch. 

 Virgula distally prolonged. Hydrothecaa inclined at an angle of 

 about 40°, overlapping each other for half their length, short and 

 tubular; free portion of each short, impressed proximally with a 

 deep excavation, the upper sinus of which is prolonged into a 



* Ann. Mag. & Nat. Hist. 1879, 1880. 



t Hopkinson, Geological Magazine, 1873, pp. 519, 520. 



Ann. & Mag. N. Hist. Ser. 5. Vol. v. 11 



