Reviews — Dr. Tornquist on the Diplograptidce. 277 



I?, IE "V I :H3 AAT s. 



I. — The Diplograptid^ and Heteropkionid^ of the Soanian 

 Rastrites Beds. By Sv. Leonk. Tornquist. Trans. Eoy. 

 Pbys. Soc. Lund, New Ser., vol. viii, 1897. 



rpHIS short monograph by Dr. Tornquist forms a welcome addition 

 L to our knowledge of the later Diplograptidee. In his Intro- 

 duction, he remarks that he has dealt only with well-pi'eserved 

 specimens, rightly laying sti'ess on the confusion created by the 

 indiscriminate determination of imperfect forms. 



In the " Rastrites Beds " the author includes the equivalents of our 

 Lower and Upper Birkhill Shales, and the lower beds of the Gala- 

 Tarannon Group. 



As regards the subdivision into zones, the classification is that 

 adopted by Tullberg in his " Skanes Graptoliter," except where recent 

 "work has necessitated a slight modification. 



The following life-zones have been detected : — 



1. Zone of Diplograptus acuminatus, Nich. (at base). 



2. Zone of Monograptus cyphus, Lapw. 



3. Zone of Monograptus triangulatns, Hai'kn. (= Lower part 



of Scottish zone of M. gregarius, Lapw.) 



4. Zone of Diplograptus folium, His. (^ Tullberg's zone of 



M. convolutus, His.) 



5. Zone of Diplograptus cometa, Gein. 



6. Zone of Monograptus SedgwicM, Port!. 



7. Zone of Monograptus runcinatus, Lapw. 



In dealing with the description of the species the author has found 

 it advisable to introduce a few new terms. He uses the terra 

 prolific side for that side of the sicula which communicates with 

 the proximal cavity of the rhabdosoma ; while he designates the 

 opposite side the dorsal side. The term virgella is suggested for 

 the so-called proximal prolongation of the virgula, which Wiman 

 has shown to be no part of the true virgula, but a special filiform 

 rod-like organ originating on the prolific side of the sicula. 



The following species are described : — 



DlPLOGRAPTID^. 



1. Climacograptus scalaris, His. 



2. Climacograptus medius, sp. nov. 



3. Climacograptus rectangularis, McCoy. 



These three species cannot be distinguished when in a fragmentary 

 condition. C. scalaris is characterized by a long distal prolongation 

 of the virgula, and a very short virgella; C. medius has a long 

 distal prolongation of the virgula, and also a long virgella; while in 

 C. rectangularis the distal prolongation of the virgula is scarcely 

 perceptible, and the virgella may be as much as 20 mm. in length. 



4. Climacograptus undulatus, Kurck. (=. C. internexus, Tornq. 



This species is characterized by its zigzag septal groove.) 



5. Diplograptus palmeus, Barr. 



