Manchester Memoirs, Vol. Ixii. (191 7) 79 



with a few longitudinal costse. Only three specimens were 

 found in the whole of the material examined and these were 

 small and weak. 



(A weak variety of N. raphanus (Linne).) 



172. Nodosaria (Dentalina) adolphina, d'Orbigny. 

 PL 4, fig- 16. 



Dentalina adolphina, d'Orbigny, 1846. Foram. Foss. Vienne, 



p. 51, pi. II, figs. 18-20. 

 D. adolphina, Sherborn and Chapman, 1886, Journ. Roy. Micr. 



Soc. [2], vol. VI, p. 750, pi. XV, fig. ua, b. 



Common in these Marls. As usual when a great number of 

 specimens are examined much variation is found to exist both 

 in the form of the shells and the nature of the surface orna- 

 mentation. In our gatherings the form varies from a slender 

 many-chambered shell with no sutural depressions in the earlier 

 portion, to a stouter shell with comparatively few globular seg- 

 ments with well-marked sutures. The former variety has the 

 whole of the later segments covered with prickles, and the 

 latter is smooth as shown in the drawing on pi. IV. Between 

 these two extreme varieties there are to be found innumerable 

 gradations both in form and surface-ornamentation. 



(Of the two forms referred to by Halkyard, the tuberculate 

 is the true A T . adolphina, as figured and described by d'Orbigny. 

 The smooth variety appears to occupy a position inter- 

 mediate between N: adolphina and N. pauperata, and some of 

 the stouter specimens are indistinguishable from the weaker 

 examples of N. pauperata in the Halkyard collection.) 



173. [Nodosaria spinosa (d'Orbigny.)] 

 173A. Nodosaria (Dentalina) spinulosa (Montagu). 



Nautilus spinulosus, Montagu, 1808, Testae. Brit. Suppl. p. 86, 



pi. XIX, fig. s- 

 Dentalina spinulosa, Sherborn and Chapman, 1886, Journ. 



Roy. Micro. Soc, [2] vol. VI, p. 751, pi. XV, fig. 13. 



Frequent, but the specimens are not typical. The 

 earlier chambers of the shells are invariably ornamented with 

 longitudinal costse, which later are interrupted or broken up 

 into short lengths, and, later still, into spines or prickles pointing 

 backwards. The prickles first make their appearance on the 

 basal portion of each segment. 



