134 



HARDWICKE'S SCIENCE-GOSSIP. 



protection, and even animals many times their size 

 have soon been disabled in their powerful and 

 pertinacious grasp. 



The species of the genus Belemnite range in Britain 

 from the Lower Lias to the Greensand (Cretaceous) 

 formations. 



They attain their maximum development in Jurassic 

 rocks, in which are found 112 species, of which sixty- 

 nine species occur in the Lias, while only eight species 

 are found in the Cretaceous. 



In the Lower Lias of England the Belemnites make 

 a rather sudden appearance, they are small in size, 

 and not at all numerous, but soon become large and 

 common, and in the upper beds of the lower Lias are 

 so numerous as to form Belemnite beds. 



The zone of Amaltheus oxynotus in the South of 

 England is called the "Belemnite beds" from the 

 abundance of B. acutus. 



The term " Belemnite beds " is given by French and 

 German geologists to the zone of CEgoceras jamesoni, 

 from their abundance both in individuals and species. 



The upper portion of the zone of CEgoceras henleyi, 

 was called by De La Beche the Belemnite bed. 



Dr. S. P. Woodward, in his "Manual of the 

 Mollusca " gives the following sections and sub- 

 sections of the species of the genus Belemnites, 

 which Phillips thought to be the best classification. 



Section 1.— Acceli (Bronn). Without dorsal or 

 ventral grooves. Sub-section 1. — Acuarii. Without 

 lateral furrows ; but often channelled at the extreme 

 point. Type, B. acuarius. Lias. Sub-section 2. 

 Clavati. With lateral furrows. Types, B. davatus. 

 Lias. 



Section 2. Gastrocceli. — (D'Orb.). Ventral 

 groove distinct. , Sub-section 1. — Canaliculati. No 

 lateral furrows. Type, B. canaliculars. Oolite. 

 Sub-section 2. — Hastati. Lateral furrows distinct. 

 Type, B. hastatus. Lias. 



Section 3. Notocceli. — With a dorsal groove, and 

 furrowed on each side. Type, B. dilatatus. Cre- 

 taceous. 



With the apparent extinction of the Belemnites 

 proper, a new genus, derived from them, appears ; 

 this is the genus Belemnitella. 



In this genus, the skeleton is very similar to the 

 Belemnites, but there is a straight fissure in the guard, 

 at its upper end, on the ventral side of the wall of the 

 alveolus, and the surface is distinctly marked with 

 vascular impressions. 



This genus is confined to the upper part of the 

 Cretaceous formation, only five species being known, 

 but they are very numerous. In this comparatively 

 little range there are recognised horizons or zones of 

 Belemnitella. 



Dr. S. P. Woodward ("Man. of Moll.") has 

 described a species of Belemnoteuthis from the Mid. 

 Oolite (Oxford Clay). 



Shell consisting of a phragmacone, like that of a 

 Belemnite, a horny dorsal pen, with obscure lateral 



bands, and a thin fibrous guard, with two diverging 

 ridges on the dorsal side. 



Authorities, however, question the validity of this 

 genus. 



Huxley (" Structure of Belemnites. Mem. Geol. 

 Survey," ,1864), has also described a species of 

 Xiphoteuthis : — guard narrow and cylindrical, con- 

 taining a very long, deep-chambered, narrow-phrag- 

 macone. Pro-ostracum greatly developed, nearly a 

 foot in length, very narrow at its base, widening out 

 anteriorly, and finally terminating in a pointed apex. 

 One species known from the Lias. 

 There are Jthree families found fossil, so nearly 

 related to the Belemnitidce, although being placed 

 before them in classification, that I may describe 

 them for the purpose of my subjects. 

 Teuthida;. (Myopsidce, D'Orbigny.) 

 Teudopsis ! (Deslongchamps) : — Pen lanceolate, 

 produced in front, dilated and spatulate behind. 

 Five species from the Lias. 



Beloteuthis (Miinster) : — Pen lanceolate, pointed 

 in front, with two small wing-like expansions behind. 

 Six species described from the Upper Lias by 

 Miinster. 



Phylloteuthis : — Pen corneous, thin, and sub-ovate, 

 slightly concave below, and convex above, the anterior 

 end narrow. 



Cretaceous formation. 



Leptoteuthis (Meyer) : — Pen horny, hastate, broad 

 in front, pointed behind. 



One species from Oxford clay. 

 Enoploteuthis (D'Orbigny) : — Pen lanceolate, 

 arms provided with a double series of horny hooks, 

 concealed by retractile webs. 



Now living in Mediterranean and Pacific. One 

 species fossil from Oolite. 



Acanthoteuthis (Wagner), Miinster : — This genus 

 is founded upon the fossil hooks of a calamary, from 

 the Oxford clay of Solenhofen. 

 Sepiadse (Myopsidse, D'Orb.). 

 Sepia (Pliny) Linnaeus : — Shell broad and thick 

 in front, laminated, and terminating in a prominent 

 " mucro." (or imperfectly chambered apex). From 

 Oxford clay, and Eocene Tertiary, attaining their 

 maximum at the present day. 



Spirulirostra (D'Orb.) : — The shell 'consists of a 

 spiral chambered portion, or phragmacone, the 

 volutions of which are separate. This is lodged in a 

 pointed calcareous rostrum. 



One species known from Miocene Tertiary. 

 Beloptera (Slainville), Deshayes : — Shell consisting 

 of a nearly straight chambered portion or phragma- 

 cone, perforated by a siphuncle, and lodged in a cal- 

 careous rostrum, which is furnished with lateral wings. 

 Spir-ulid^. Spirula (Lamarck, 1S01). — Shell 

 nacreous, discoidai, composed of volutions not in 

 contact with each other. The shell is divided into 

 chambers by curved shelly partitions, pierced by a 

 ventral siphuncle. 



