ON THE GENUS EAMFLINA. 353 



§ 4. Occurrence q/'Ramulina. 



Mamulina, so far as at present ascertaiaed, makes its first 

 appearance in strata of Jurassic age, having been found in the 

 Transversarins-zone of Switzerland and the Oniatus-zone of 

 Poland. It occurs in the Neocomian (Bargate) Pebble-beds of 

 Littleton and Chilworth, Surrey *, and in many succeeding 

 formations. Thus we know of it as specimens from various 

 other Cretaceous deposits, such as the G-ault of Folkestone, 

 Merstham, and Grodstone ; and as figures and descriptions of 

 examples from the Gault of Prance and Switzerland. We have 

 specimens also from the Chalk-marl of Charing and Folkestone, 

 and the Chalk of Kent, the Phosphatic Chalk of Taplow, 

 Buckinghamshire, and the Chalk of Ireland. The Chalk of 

 Aix-la-Chapelle and that of Bohemia have also yielded definite 

 forms which have been figured. 



The RamulincB above referred to are mostly of the types that 

 have the test covered with short prickles : one with the shell 

 thin {globulifera) ; and the other, which we recognize as i?. acu- 

 leata, with a thick test. Since the identity of any of these 

 forms with d'Orbigny's Dentalina aculeata is not regarded as 

 satisfactory by some authorities, and as Mr. Joseph Wright has 

 figured a specimen of the latter kind as " JS. aculeata (d'Orb.)," 

 we use that specific name for these prickly HamuUnee, without 

 reference to d'Orbigny's named specimen, thus, S. aculeata, 

 Wright. 



Note. — As regards the distribution of MamulincB in the Gault 

 of Folkestone, it is interesting to note the gradual increase in 

 their numbers from Zone III. (where they first make their 

 appearance in this formation) to the top of the Gault at its 

 junction with the Chloritic Marl ; and so, increasingly, upwards 

 to the Upper Chalk. 



§ 5. Distribution and Range in Time of B,a.mulina. 



1. Eamulina L^vis, Jbwes. Chalk; Ireland. Tertiary; Austria. 



Recent; Ireland. 



2. E. GLOBULiFEEA, Brady. Jurassic ; Poland and Switzerland. 



Lower Greensaud ; Surrey. Gaulf; Folkestone and France. 

 Tertiary ; England, Austria, Italy, and Sicily. Recent ; 

 Mauritius, West Australia, Lancashire, Atlantic, and Pacific. 

 * Quart. Journ. Geol. Son. vol. 1. 1895, pp. 717, 718. 

 LINN. JOUBN. — ZOOLOGT, VOL. XXVI. 26 



