136 MR. H. KTNASTON ON THE [May 1 894, 



Amongst the gasteropoda, Ampullina (or Amauropsis, origirjally 

 Natica) hulbiformis (Sow.) and Natica lyrata (Sow.) occur in 

 thousands ; also Cerithium reticosum (Sow.). Zekeli described about 

 47 species of Cerithium from these beds, but these were reduced to 

 about a third of that number by Stoliczka, on the ground that many 

 of the species were founded on broken fragments of the spines of 

 other species, or were established on insufficiently constant characters. 

 Thus the species Cerithium reticosum (Sow.) includes C. pustulosum 

 (Sow.), which is merely a variety and passes imperceptibly into the 

 type, C. cribriforme (Zek.), C. luciclum (Zek.), C. clcedalum (Zek.), 

 and several others. Glaucoma (or Omphalici) Kefersteini (d'Orb.) 

 is found with Actceonella at Traunwand and in the brackish-water 

 beds of the Estuarine series at Neue Welt. JVerincea nobilis 

 (Miinst.) and N. Buchi (Kefst.) both belong to the limestone-beds 

 (Nerincea-limestone), which come above the lowest Hippurite-lime- 

 stone. Nerincta flexuosa (Sow.) and N. gracilis (Zek.) seem to 

 belong to definite zones, in which they occur in swarms, rather low 

 down in the fossiliferous marl series. Actceonella is very charac- 

 teristic : A. gigantea (Sow.) occurs in great numbers in con- 

 glomerate and coarse sandstone, frequently in a rather crushed 

 condition, in the Rontograben. Volvulina Icevis (d'Orb.), originally 

 assigned to the genus Volvarla and then to Actceonella, is also of 

 rather local occurrence, but is very common where it does occur. 

 Aporrhais (Alaria) costata (Sow.), originally assigned to Rostellaria, 

 is extremely common in most localities. Several species of Voluta 

 were described by Zekeli, but these have all been assigned to other 

 genera by Stoliczka, such as Volutilithes, Neptunea, Mitra, etc., 

 thus : — 



Voluta. Bronni (Zek.) = Volutilithes acuta (Sow.). 



raricosta (Zek.) = Casparmi (d'Orb.). 



crcnata (Zek.) = Neptunea crenata (Zek.). 



cristata (Zek.) = Mitra cancellata (Sow.). 



Fums cingulatus (Sow.) is very common, especially in the Edel- 

 bachgraben ; Stoliczka, however, doubts whether this form really 

 belongs to the genus Fusus. 



The outer shell of both gasteropoda and lamellibranchiata is, on 

 the whole, by no means well preserved in the fossiliferous marls, so 

 that specific identification is frequently somewhat difficult. Perhaps 

 the lamellibranchiata are generally the better preserved of the two, 

 the gasteropoda being more apt to get broken or merely to be 

 preserved as casts. Cerithium and Turritella are generally fairly 

 well preserved, and the shells of Melania and Tanalia in the coal- 

 bearing beds of the Neue Alp are exceedingly tough, though gener- 

 ally rather flattened by pressure. 



By far the larger majority of the Gosau fossils are peculiar to 

 these beds, only about 124 species out of considerably over 500 

 occurring in other formations outside the Eastern Alps, and the 

 distribution of these we shall have now to consider in discussing 

 the geological horizon of the beds. 



