76 ME. H. WOODS ON THE MOLLUSCA [Feb. 1 896, 



inferior-lateral lobe, both deeply divided, the divisions bifid and 

 not quite symmetrical. Siphonal saddle a little larger than the 

 superior-lateral saddle, both narrow-stemmed and deeply and un- 

 symmetrically divided. 



Affinities. — This species is near to Astierianus of d'Orbigny x from 

 the Upper Gault of Escagnolle, but it is distinguished by the wider 

 umbilicus and by the change in direction of the ribs on some of the 

 whorls. It is also allied to Helicoceras indicum, Stoliczka, 2 from the 

 Arrialoor Group of Vegahoor, with which it may prove to be iden- 

 tical when that form is better known. H. Beussianum differs in 

 having the varices continued on the spire, just as on the free 

 whorls. 3 



Distribution. — Chalk Rock of Winchester, Lichfield (Hants), 

 Ouckhamsley, Luton cutting, and Hitchin. 



Genus Baculites, Lamarck, 1801. 



Baculites bohemicus, Fritsch and Schlonbach, 1872. (PI. II. 

 figs. 9, 10.) 



1843. Baculites anceps, H. B. Geinitz, ' Die Verstein. von Kieslingswalda,' p. 9. 



1850. Baculites baculoides, H. B. Geinitz, ' Das Quadersandst. oder Kreidegebirge 

 in Deutschland,' p. 122 ; 1874. H. B. Geinitz, ' Das Elbthalgebirge in Sacbsen ' 

 (Palaeontographica, vol. xx.), part ii. p. 195, pi. xxxv. f. 17-21. 



1872. Baculites Faujassi, Lamarck, var. bohemica, A. Fritsch and U. Schlonbach, 

 ' Ceph. der bohrn. Kreideformat.' p. 49, pi. xiii. f. 23-25, 29, 30; 1893. A. Fritsch, 

 ' Stud, im Gebiete der bohm. Kreideformat. V. Priesener Schichten,' p. 80, f. 63 ; 

 1895. J. J. Jahn, Jahrb. der k. k. geol. Reichsanst. vol. xlv. p. 133, pi. viii. f. 8. 



1875. Baculites bohemicus, C. Barrois, Ann. Soc. Geol. du Nord, vol. v. p. 403. 



1876. Baculites cf. bohemicus, C. Schluter, ' Ceph. oberen deutsch. Kreide,' p. 140, 

 pi. xxxix. f. 1-5. 



Description. — Shell increasing in diameter very slowly, section 

 elliptical, siphonal margin rounded ; last chamber with a curved 

 projecting portion on the siphonal side. Surface of shell with 

 faintly marked ribs or undulations, which pass over the siphonal 

 margin, where they are strongest, and curve posteriorly on the 

 lateral areas, becoming indistinct or altogether disappearing on the 

 anti-siphonal margin. There are also at intervals broad furrows, 

 which run parallel to the ribs and become less distinct on the anti- 

 siphonal margin (these, however, are not seen on all specimens). 



Suture-line: — siphonal lobe rather broad, divided by a median 

 saddle; superior-lateral lobe rather deep, bifid, larger than the 

 inferior-lateral ; internal (anti-siphonal) lobe small ; siphonal saddle 

 broad, deeply bifurcate, each part being also bifid ; lateral saddles 

 similarly bifurcate, the superior-lateral being about half the size 

 of the siphonal saddle. 



Affinities. — This species is related to Baculites vertebralis, Lamk. 

 (=Faujasi, Lamk.), and to B. baculoides, Mant. It differs from 

 B. vertebralis in having the siphonal saddle nearly twice as broad as 

 the superior-lateral saddle, and the ribs and grooves appear to be 



1 « Pal. Franc. Terr. Cret.' vol. i. (1840) p. 578, pi. cxl. f. 8-11. 



2 'Fobs. Ceph. Cret. Kock. S. India' (1866), p. 184, pi. lxxxvi. f. 1-2. 



3 See Schluter, ' Ceph. oberen deutsch. Kreide ' (1871), pi. xxxii. f. 14-16, 20. 



