SONNINIA GIBBERA. 421 



1. Cost* regular. 

 Sonninia reclinans, 8. Buchnaii. Plate XCVIII, fig. 7 ; Plate CII1, fig. 21. 



1892. Sonjjinia crassispinata (pars). This Monograph, Plate XLVIII, figs. 16, 



17 ; Plate LXV, figs. 3, 4, 1 and p. 318 

 (pars). 



As the type of this species I take the form figured in PL XLVIII, figs. 16, 17, 

 of which part of the septal margin is shown in PI. XCVIII, fig. 7. This was one of 

 the forms alluded to as crassispinata a in p. 318, and the differences between it and 

 crassispinata /3 were pointed out. Practically these consisted of a greater duration 

 of the irregular spinous stage in what is now reclinans ; and to this has to be added 

 difference in septation, L with more intra-axial, anisosceloid terminal lobule. 



As crassispinata a there was also reckoned (p. 318) what is now, on the 

 evidence of its suture-line coupled with its ornament, presumed to be the young of 

 Bonn, locuples (p. 431). That form differs from crassispinata /3 in the same way 

 as what is now reclinans, namely, in having a long and marked irregular spinous 

 stage ; but it differs from reclinans in septation, L has a less anisosceloid, more 

 axial terminal lobule, and in having the non-spiniferous costa? stronger. Although 

 the latter difference is not very marked in the young fossil compared to reclinans, 

 and the drawings in the plates may give a somewhat false idea, yet the differ- 

 ence between reclinans and adult locuples in this respect is particularly noticeable. 



With reclinans, and under the same name, what was described as crassispinata y 

 (p. 318), may now be associated as a variety. It was noticed at the time as 

 a descendant of crassispinata a, and not of /3. From type reclinans it differs 

 in being more quickly coiled and more compressed, its flatter-sided whorls being 

 particularly noticeable. Its septa are shown in PI. CIII, fig. 21 : they agree 

 with the suture-line of the type reclinans (PI. XCVIII, fig. 7), except in the greater 

 breadth of the siphonal saddle — a feature certain to be associated with flatter 

 whorls. 



Sonninia gibbera, 8. Buchnan. Plate LXXXVII, figs. 4, 5 ; Plate LXXXVIII, 



figs. 1 — 3. 



Discoidal, compressed, hollow-carinate. Whorls ornamented with small, direct, 

 reclined, ventrally-inclined costse and spinicostge about as 2 or 3 to 1 on the inner 

 side of the spine. The spinicostse are larger than the costas, and are somewhat 

 strongly spined ; beyond the spine they are often obscurely bifurcate. Ventral 



1 It ia requested that the explanation of the plates be altered in accordance. 



