842 MESSES. HANCOCK AND HOWSE 



anterior division, which in size decrease backwards, and stand in 

 five transverse rows. Their upper enamelled end seems in all 

 to be bent forwards, or in the opposite direction to those of the 

 anterior group of teeth. Miinster ascribes such a curvature to 

 two teeth only, which in his specimen are situated immediately 

 between the two divisions of the palate and out of place (Beitr. 

 V. p. 39, tab. 15, f. 13, g, h) ; but he announces expressly that 

 this palate is a little drawn out and dislocated, for which reason 

 the teeth are not in their usual regular position. 



"In our Janassa, the original of J. Humholdti, Miinster, all 

 the remaining teeth of the first cross row of the posterior divi- 

 sion, from the line a h, have an equal curvature forwards of their 

 upper part. The teeth of the cross rows standing behind them 

 are only marked by broken roots. This specimen shows yet 

 another character of the genus Janassa, which has not yet been 

 described in any other specimen. At the posterior part of the 

 head, or rather at the entrance of the throat, there are two large, 

 similarly formed, bent teeth (d d), like all the others of the pos- 

 terior division, which Count Miinster took for ear-bones (Beitr. 

 i. 1843, p. 122). 



"On the specimens which are broken through parallel to the 

 palate-plate, as in ' Dyas,' tab. 5, f. 1, the six-sided form of the 

 teeth shows itself clearly ; but the boundary between the anterior 

 and posterior divisions of the teeth shows itself also on these 

 very distinctly, as the front teeth of the former have the anterior 

 side concave and the hinder convex ; but on the latter this ap- 

 pears reversed {ib. tab. 5, f. 1). In Miinster's figures this rela- 

 tion is only taken into consideration in J. Dictea. 



"In our J. Huviboldti {ib. tab. 4, f. 5) the first cross row of 

 teeth of the posterior division is by pressure driven close to the 

 last cross row of the anterior division, and partly under it, for 

 which reason one cannot see the separating furrow ; and Count 

 Miinster has felt himself justified in placing J. Hmnboldti with 

 Dictea (Beitr. v. p. 38). 



"From the similar form of the teeth of Miinster's Janassa 

 and Dictea, of which the structure is always tubular, while the 

 outer surface of the root shows more or less distinct transverse 



