90 



BRTTTSTT ORAPTOLTTES. 



Bryograptus divergens, 



HOY. IMate XII, fio-. 



1894. 1 Bryograjitus Cnllavci, Marr, Gool. Mag., p. 130, fig. G. 



1898. Bnjoijraptm, cf. CaJlavel, Ellos, Quart. Journ. Geol. Soc , vol. liv, p. 470, fig. 2. 



Main stipes 1'4 cm. in length, flexed, slender, not exceeding- 'G mm. in width, 



diverging from the sicnla at al^ont 1)0°; from their inner thecal margins 



nn symmetrically disposed lateral branches are given off. Thecae twelve to 



thirteen in 10 mm., inclined 20°, overlapping one third to one half their 



length, having an average length of To mm. ; five times as long as wide, of 



uniform breadth, and with outer walls slightly curved. Apertural margins 



straight, oblique, with nmcronate denticle. 



i)e6'cr?j}^{o?i.-^Unfortunately one specimen only of this species is known, and 



that shows merely two incomplete lateral branches arising at different levels on 



each of the main stipes. 



The sicula is incomplete, but must have been at 

 least 1"2 mm. in length. 



Bemarls.— This species was at first regarded as a 

 possible variety of Lapworth's Br. GaUavei. Since 

 that form is now known not to be a Brj/ograptus 

 (see p. 84), it is necessary to give this specimen a 

 new name. B. divergens differs from other British 

 Bryograpti in the wader divergence of the main 

 stipes. 



Horizon and Localiti/. — Tremadoc (P). Lower Skiddaw Slates. 

 LaJce District : Barf. 



Associates, etc. — The solitary specimen of ]h-. diverge)is at present known is in 

 the Woodwardian Museum. It was found in the Skiddaw Slates, but its associates 

 are unknown. 



Fig. 52. — Bryograptus divergens, s-p.nov. 



Proximal end, obverse view 

 ment of PL XII, &s 



Genus TRICHOGRAPTUS, Nicholson. 

 1876. Tricluxjrapiun, Nicliolsou, Geol. Mag., dec. 2, vol. iii, p. 248. 



Polypary bilaterally symmetrical, consisting of two very slender, reclined, 

 uniserial main stipes, from the thecal margins of which long, slender, flexed 

 lateral branches are given off. 



Thecas approximately of the simple Dichograptid type, overlapping for a very 

 small fraction of their length. 



