ANNIVERSARY ADDRESS OF THE PRESIDENT. 



83 



Lingula pygmmi, Salt., Obolella Salteri, Holl, and Spondylobolus, sp. ; 

 many of these are peculiar to the Malvern area. Dr. Holl* in 1865 

 described the geological structure of the Malvern Hills and adjacent 

 districts, placing these shales in the Upper Cambrian, the Hollybush 

 sandstone being the base or lowest known sedimentary rock in the 

 Malvern area. Whether Dictyonema should be classed with the 

 Bryozoa or Hydrozoa is still a doubtful question. 



Brachiopoda. — Only 5 genera and 8 species occur in the Upper 

 Lingula beds — Kutorgina cingulata, Lingulella Davisii, L. lepis, 

 Lingula pygmmi, Obolella plicata, 0. Salteri, 0. sagittalis, and Orthis 

 lenticularis. 6 pass to the Tremadoc rocks — Kutorgina cingulata, 

 Lingulella Davisii, L. lepis, Obolella plicata, 0. sagittalis, Orthis 

 lenticularis ; only 2 species are really restricted to the Upper Lin- 

 gula-flags, Lingula pygmcea and Obolella Salteri. No zoological 

 value can therefore be attached to the Brachiopoda, as all the species 

 but 2 occur both below and above the Upper Lingula-flags. 



Lamellibranchiata. — None have as yet been detected. 



Gasteropoda. — None known below the Arenig. 



Pteropoda. — Of the 4 genera and 17 species that range from the 

 Longmynd group of St. David's to the Upper Tremadoc no form has 

 yet been discovered in the Upper Lingula-flags. 



Heteropoda. — None have occurred, although 5 species range 

 through the Lower Cambrian rocks. The so-called Middle Lingula- 

 flags have yielded one species, Bellerophon cambrensis, Belt, which is 

 the first known species on record. 



Cephalopoda. — None of any type. No species occur below the 

 Lower Tremadoc. The entire Cephalopod fauna of the Lower Cam- 

 brian rocks consists only of 1 genus and 2 species below the Arenig 

 rocks, Orthoceras precox, Salt., and 0. sericeum, Salt. ; in the Upper 

 Tremadoc these increase to 5 species. 



Between the close of the deposition of the Menevian rocks and the 

 close of the Upper Lingula-flags, 10 new genera appeared, viz. 3 An- 

 nelida, 1 Bryozoon, 4 Crustacea, and 2 Brachiopoda f, succeeded by 

 13 new species in the Tremadoc (Echinodermata 2 species, Crustacea 4, 

 Lamellibranchiata 5, Cephalopoda 2 species). The known newly intro- 

 duced genera in the Lingula-flags were, Cruziana, Scolicoderma, Hel- 

 rninthites, Dictyonema, Parabolina, DikelocephaZus, Peltura, Hymeno- 

 caris, Lingula and Kutorgina. Only 1 of these {Lingula) lived on 

 after the deposition of those sediments we term Lingula-flags ; this 

 genus has appeared in almost every successive marine formation. 



The Lower Lingula beds have yielded 17 genera and 36 species, and 

 the Upper Lingula-flags 16 genera and 41 species, showing a generic 

 loss or dying out of 7 genera in their upward succession ; they ap- 

 pear to be Protospongia, Cruziana, Helrninthites, Anopolenus, Holo- 

 cephalina, Hymenocaris, and Leperclitia. 



* Quart. Journ. Geol. Soc. vol. xxi. 1865, pp. 72-102. 



t Cruziana (semiplicata), Scolicoderma {tuberculatum and antiquissimum), 

 Helrninthites (sp.), Dictyonema (sociak), Hymenocaris (vermicaitda), Olenus (cata- 

 ractes), Dikelocephakcs (celticus and discoidalis), also Carausia (menevensis), with 

 Lingula and Lingulella. 



