OTOZAMITES. 41 



(young fronds). Veins divergent in the basal portion of the pinnae, 

 extending in an oblique direction to the upper and lower edge of 

 the lamina. 



Ototamites ohtusus, founded by Lindley & Hutton on a specimen 

 from the Lias of Axminster, and now preserved in the Oxford 

 Museum, forms one of several species of the genus which are so 

 -closely linked together that it is often impossible to recognise 

 satisfactory distinguishing features. 



The type-specimen of Otoxamites ohtusus consists of a portion 

 of a frond 8 cm. long, with very clearly preserved pinnas. 



Otozamites graphicus, a characteristic Inferior Oolite species, 

 represents a type of frond very similar in shape and in the form 

 and venation of the pinnae to 0. ohtusus. Erom Jurassic rocks of 

 France, Italy, and elsewhere, numerous examples of Oto%am%tes have 

 been described which demonstrate the abundance of this generic 

 type, and the impossibility of defining the limits of the various 

 species. Attention has elsewhere been drawn to the futility of 

 attempting to recognise specific distinctions in the slight variations 

 in shape which are met with in the pinnae of Otozamifes fronds, 

 and, to avoid the danger of carrying artificial differences too far, • 

 I have suggested the use of the specific name ohtusus in a com- 

 prehensive sense. 



Specimens of Otozamiies ohtusus from the Lias of England are 

 fairly common ; in addition to the well-preserved fronds in the 

 British and Oxford Museums, examples are included in the 

 collections in the Jermyn Street Museum and in the Museums 

 of Bath, Bristol, and Cardiff. 



40,672. PL I. Eig. 1. 



An almost perfect frond 24 cm. long and 3-1 cm. broad at its 

 widest part. The pinnae are obtusely pointed, slightly falcate, 

 and have a prominent lobe on the upper edge of the base. Veins 

 spreading from the centre of the base, cutting the edges of the 

 pinnae obliquely. 



Near Lyme Eegis. Purchased, 1859. 



[1155. Pi. I. Eig. 2. 



A specimen from near Baireuth ; the figure represents a portion 

 of a frond 20 cm. in length. This is undoubtedly the species 

 iigured by Schenk as Otopteris Buchlandi, but it is probably not 



