SUPPLEMENT.— CRICKIA. lxxiii 



2. Rhjsbooekas tolutakium (Dumortier). Suppl., Plate XI, figs. 4 — 6. 



1874. Ammonites Murchisonje, Dumortier, fitudes pal. Baasin du Rhone, pt. 4, 



pi. li, figs. 3, 4 (non 5, 6). 

 1874. tolutarius, Dumortier, in Coll., p. 256. 



Description. — Platysubleptogyral, subangusturnbilicate, subparvicostate. 



Distinction. — From Bit. tortum, greater compression and less coarse ornament. 



Remarks. — Dumortier says, 1 " The compressed regular Ammonite of Verpillicre 

 which is abundant at Crussol, and of which I give a drawing in pi. li, figs, 3, 4, 

 is remarkable for the shape of its ornament, and for its angular ribs. These ribs 

 appear as if articulated in front at the places where they bifurcate, and they thus 

 represent very fairly the arm and shank of a horse on the trot. Accordingly 

 I placed this shell, in my collection, under the name of A. tolutarius, and though I 

 only refer to it here as a variety of ^4. Murchisonae I am not averse from believing 

 that, later on, it will be convenient to separate this form as a distinct type ; the 

 fear of overmultiplying species alone prevents me from so doing at present." 

 He considered this and the preceding species to belong to tolutarius; but the 

 one from la Verpilliere (his figs. 5, 6) is certainly coarser ribbed and nearly 

 twice as thick as that from Crussol (his figs. 3, 4). The latter, which he says is 

 common, I have chosen as the type. 



Locality and Stratum. — Burton Bradstock, in the L. uncinatum bed. 



Date of Existence. — Scissi hemera. 



XXVI. (leans — Oeickia, 2 S. Buchnan. 

 (Type — Cric/cia refiua, sp. n.) 

 1899. Crickia. This Monogr., Explan. of Suppl. PI. xi. 

 Definition. — Subplatysubleptogyral, sublatumbilicate ; subdensi- 

 septate, longi-subangusti-lobate; laterally anguliradiate; peripherally 

 latanguliradiate, subtabulate, parvi-nousepti-carinate. 



Distinction. — From Bhxboceras, the radial line has rather less 

 peripheral projection, and the lateral bend falls further forward of 

 the straight line. From Ludwigia, the mode of growth is fig. 29. -Radial 

 different; there is a wider umbilicus and greater compression. cwaw* rejiua. 



1. CiucKtA reflua, 8. Buchnan. Suppl., Plate XI, figs. 16 — IS. 



Description. — Subplatysubleptogyral, sublatumbilicate, costate. 

 Remarks. — Two costse are generally joined on the inner lateral area to form a 

 1 Pp. 256, 257, pt. iv. 2 In honour of Mr. G. C. Crick, F.Cr.S. 



