J. StarUe Gardner — Cretaceous Gasteropoda. 75 



resembles a mass of sporting powder compacted together. When 

 the larger coprolite nodules are cut in two, they too are often found 

 to be composed of similar round grains, whence the conclusion may 

 be drawn that the phosphatic strata were formed by the washing- 

 down of excrements of Saurians and fish. At two other places the 

 slate beds have intercalated between them strata of grey gypsum of 

 little thickness (at most 2 metres) containing nodules of coprolite. 

 At the same places, especially in the above-mentioned round nodules, 

 there are also found small quantities of rock oil, and the black slates 

 are sometimes so bituminous that they can be used as fuel. 

 {To he continued in our next Number.) 



IV. — -Cketaceous Gasteropoda^ 

 By J. Starkie G-abdnee,, F.G.S. 



FOLLOWING- up the notes which recently appeared on Creta- 

 ceous Aporrliaidm,^ I now propose to continue from time to time 

 notes on other Cretaceous Gasteropoda. At present I have se- 

 lected for illustration " Scalariform Shells." The most recent papers 

 which refer to this subject are witnesses how much revision of the 

 genera and species is needed to which our British Cretaceous repre- 

 sentatives of this type have been assigned. I first take the family 

 of Scalidce, and will, as briefly as possible, endeavour to recapitulate 

 what is at present known of this family. 



Family Scalidce, H. and A. Adams, 1857. 



(Genera of Mollusca, vol. i. p. 220.) 



Bibliography. — Synonyms : Scalaridce, Chenu, Man. Conch, p. 217. 



Scalaridce, Gray, Guide, 1857. 



The group of Scalaria was separated by H. and A. Adams from the 

 TurritellidcB, and is now made to include thirteen recent and fossil 

 genera and several sub-genera. There are still great differences of 

 opinion with regard to the position of this group ; the majority of 

 authors retain it in the family of TurritellidcB ; others regard it as a 

 distinct family, but retain it next the TurritellidcB ; whilst Adams and 

 Chenu place it away from th^ TurritellidcB, and next to the Terebridce. 



Description. — The shell is solid, spiral, and turreted ; the whorls 

 convex, sometimes disconnected, usually with numerous transverse 

 ribs ; the aperture rounded, with entire margins ; peristome gene- 

 rally broadened and recurved, without any canal or notch. The ribs 

 represent the growths of the shells, marking the successive points oc- 

 cupied by the mouth. The shells are usually white, and are remark- 

 able for extreme elegance of form and delicacy of sculpture. The 

 operculum is spiral, horny, of few whorls. The animals are carni- 

 vorous, and have been known to feed upon fresh beef; they greatly 

 resemble those of Tur7itellidce, the principal differences being exhibited 

 in the dentition. All the animals of this group yield a purple dye. 



Distribution. — Their vertical range is from low-water to 80 fathoms, 

 their geographical range embraces every sea, but they are more 

 developed in the Indian Ocean, China, and the Philippines. Five are 

 1 See Geol. Mag., 1875, Decade II. Vol. II. pp. 49, 124, 198, 291, 392. 



