586 MESSES. E. HEEON-ALLEN AND A. EAELAND ON THE 



and tubular than usual, and only compressed at the oral extremity. Such individuals 

 raise the question whether A. sagra is anything more than an advanced bimorphous 

 form of A. sulcata. 



95. Articulina conico-articulata (Batscli). (Pi. XLV. figs. 26-33.) 



Nautilus conico-articulatus Batscli, 1791, CS. p. 3, pi. iii. fig. 11. 

 Articulina nitida d'Oibigny, 1826, TMC. p. 300, no. 1, Modele no. 22. 



„ „ Parker, Jones, Ss Brady, 1859, etc., NP. 1865, p. 22, pi. i. f5g, 2. 



Vertebralina {Articulina) elongata Karrer, 1868, MFKB. p. 155, pi. iii. fig. 10. 

 Articulina conico-articulata Brady, 1884, FC. p. 185, pi. xii. figs. 17, 18 ; pi. xiii. figs. 1, 2. 



„ „ „ Millett, 1898, etc., FM. 1898, p. 511, pi. xii. figs. 9, 10. 



„ „ Lister, 1908, F. p. 93, fig. 28. 



17 Stations. 



This very variable species occurs at every Stn. in one or other of its forms, and at 

 most Stns. nearly all the varieties occur together. 



Batsch's original figure is of the many-chambered type with cylindrical chambers, 

 regularly increasing in diameter, but the specimen from which he drew his figure 

 is broken and the initial portion is not shown. D'Orbigny, under the name 

 A. nitida (d'O. 1826, TMC. p. 300. no. 1, Modele no. 22), issued a Model which 

 represents the same type, but has somewhat more turgid chambers constricted at 

 the sutural joints, and with a prominent milioline initial portion. Both Batsch's 

 figure and d'Orbigny's Model represent shells circular in section. Yet a third type is 

 the A. elongata of Karrer, which may best be described as a curved or dentaline variety 

 of Batsch's form ; the initial portion is not shown by Karrer, but the chambers are 

 circular in section. A fourth form is figured by Brady (pi. xiii. fig. 1) which may be 

 briefly described as a dentaline and elongated form of d'Orbigny's Model. Millett 

 figures yet another type which may be regarded as a modification of d'Orbigny's 

 Model, characterized by the fusiform shape of the chambers and the great constriction 

 of the apertural end of each chamber, as compared with its inflated base. Millett's 

 specimens were apparently straight. 



The Kerimba specimens cover the M'hole of the foregoing varieties and present some 

 further modifications. Dealing first with the Batsch type, which is the most abundant 

 and furnishes the largest specimens, there is a distinct tendency at some Stns., notably 

 1, 2, 4, 5, 6, 9, 10, and 12, towards compression of the later chambers, which then 

 become oval in section, passing in extreme cases into a compressed final chamber, 

 practically indistinguishable from A. sagra d'Orbigny. The circular type occurs at 

 every Stn. except four, usually in abundance ; at Stns. 5, 6, and 10 it attains a 

 comparatively large size, but at Stn. 9, where it is a common species, all the specimens 

 are small. 



Of the dentaline varieties, Karrer's type is very rare, but Brady's occurs at all Stns. 

 except 3 and 11. The only Stn. at which it is very common is Stn. 7, common at 



