C. Lapworth — On Scottish Monograptidce. 503 



polypary ; the apertural portions of the early hyclrothec^e scarcely 

 project at all above the ventral margin, while the aperture is 

 slightly everted, and there is a minute and very conspicuous denticle. 



M. Barrandei was founded by Suess upon a proximal fragment 

 possessing the characters noted above ; but judging from his guarded 

 reference to Rastrites gemmatus, Barr., as being merely one of its 

 varieties, it is probable that he was aware of the occasional lobe- 

 like form of its distal hydrothecse. He regarded it as a species 

 uniting the characters of the proximal portion of Monograptus pro- 

 tens, Barr., and those of a true Bastrites (a genus he refused to 

 recognize), believing that the distal projections made up the whole 

 body of the hydrothecse, which were thus isolated and separated 

 from each other by long and barren internodes.^ 



Locality. — Very rare in the Gala Group at Buckholm, Meigle, 

 and Grieston. 



31. Monograptus exiguus, Nicholson, sp. Plate XX. Fig. 6. 



Graptolitlius lobiferus, var. exiguus, Nicholson ; Quart. Journ. 



Geol. Soc. vol. xxiv. pi. xix. figs. 27 and 28. 

 Graptolitlius plumosus, Baily ; Mem. Geol. Surv. Ireland, 



Explan. Sheets 49, 50, p. 23, figs, la — b c 



Polypary about one inch in length, slender, with incurved proxi- 

 mal extremity. Hydrothecse 35 to 40 to the inch, proximal portion 

 adnate to the periderm, distal portion isolated, and forming a small 

 rounded lobe. 



The periderm in this very distinct little species is a mere line, and 

 the breadth of the whole polypary, inclusive of the projection of the 

 hydrothecEe, is less than one-fortieth of an inch. The incurved 

 proximal portion embraces about one-fifth of the total length, which 

 never amounts to more than an inch and a half. The hydrothecaa 

 are almost identical in shape with those in M. BecJci, but the lobes 

 are a little larger proportionally. 



The size and shape of the polypary and its minute closely- set 

 hydrothecae efi'ectuall}'- distinguish M. exiguus from all its congeners. 



Mr. Baily gives an excellent figure of this species (loc. cit. supra). 



Locality. — M. exiguus occurs in great profusion in the beds of the 

 Gala Group at Caddonfoot. Meigle, Glendearg, Grieston, Douglas 

 near Tushielaw, Glenkiln, etc. 



32. Monograptus crispus, sp. nov. Plate XX. Fig. 7. 



Polypary extremely slender, less than one inch in length ; proxi- 

 mal portion almost straight, distal portion incurved. Hydrothecse 20 

 to 30 to the inch, in proximal portion adnate, in distal portion free for 

 half their length: outer extremity of each inrolled in a minute lobe. 



The general form of the polypary in this species is strikingly 

 characteristic. For the first tenth of an inch it is bent backwards, 

 so that the earlier hydrothecas lie upon the convex margin of the 

 periderm. The following half-inch is perpendicular and slightly 

 arcuate, and the final portion forms a complete semicircle which 

 carries the hydrothecse upon its inner edge. 



^ Suess, Bohmische GraptoHthen, s. 126. 



