W. H. Hudleston — On the Yorkshire Oolites. 203 



larger ones. The shortest specimen in the Leckenby Collection 

 measures about 7 mm. 



Relations and Distribution. — This is probably the most abundant 

 representative of the Tornatellidge in the Yorkshire Dogger, though 

 far from being common. As we have seen, it varies greatly in size. 

 The question of spiral striation is in a great measure a question of 

 conditions of preservation. The larger the specimen the less likely 

 it is to exhibit this feature. A very fine and close system of spiral 

 striation may therefore be regarded as one of the characters of Act. 

 Jiumeralis, serving together with other peculiarities to connect it 

 with Act. Sarthacensis, which is probably a representative, rather 

 than an identical species, possessed of a smaller habit of growth. 



I am inclined to think that Act. chrysalis is even more closely 

 related. Tate and Blake's species is described as follows : " Shell 

 oblong-ovate, whorls 5, subconvex, depressed at the suture, with 

 a single impressed line on the shoulder of the whorl, marked with 

 transverse plications and fine striae." The single impressed line at 

 the shoulder produces, it is believed, the kind of double tabulation 

 so characteristic of Act. humeralis. 



Two examples of Act. chrysalis are recorded by Tate and Blake 

 from the Spinatiis-zone of Eston and Upleatham. 



86. — AcT^ONiNA, sp. Plate V. Fig. 2. 



Description. — Specimen from the Dogger (zone 1), Peak (Blue 



Wyke). Bean Collection, British Museum. 



. • , ( Heiffht 12 miUimetres. 



Approximate ( gp.«^^ ^^g^^ 7go_ 



Shell oval and composed of about 6 whorls. Spire regular, apex 

 moderately acute. Whorls smooth, tumid, and sloping in the direc- 

 tion of the mean spiral angle, with no trace of tabulation on the 

 whorls of the spire : suture conspicuous. Body-whorl large, ovate, 

 and marked by broad lines of growth, which are nearly straight. 

 Other indications wanting. 



This form is distinguished from Act. humeralis by its wider spiral 

 angle, by the tumid and non-tabulate character of the whorls, and by 

 its freedom, even in a well-preserved specimen, of any trace of 

 spiral ornamentation, and by the broad lines of growth. 



The specimen is the only one of the kind from the Dogger ever 

 seen by me. As a temporary name, it might be distinguished under 

 the title of ActcBonina tumescens. 



87. — AcTiEONiNA GiGANTEA, Deslongchamps, 1842 (obtuse variety). 



Not figured. 

 1842. Tornatella gigantea, Deslongchamps, Mem. Soc. Linn. Norm. vii. p. 137, 



pi. 10, figs. 27 and 28. 

 1850. Aclceonina gigantea, Desl. Morris and Lycett, Gt. Ool. Moll. p. 119, pi. xv. 



fig. 13. 

 1852. Actceoitina Deslongchampsii, D'Orbigny. Terr. Jur. ii. p. 171, pi. 286, fig. 11. 

 1875. Actceonina gigantea, Desl. PhilKps G. Y. 3rd ed. p. 260. 



The specimen, originally described and figured by Deslongchamps, 

 was from the Great Oolite of Ranville, where D'Orbigny says it is 

 always found as a cast. He objected to Deslongchamps' name on the 



