276 SCALPELLUM VILL0SUM, 



lies by itself, a little beneath this whorl. The latera are 

 smaller than the rostrum or the sub-carina. They are 

 placed far distant from each other ; their inner surfaces 

 are triangular ; their umbones point upwards ; the rostral 

 pair is smaller than the other two pair, which are of 

 equal size. The exact position of the rostral latus differed 

 on the two sides of the specimen examined ; apparently 

 its normal position is at the baso-lateral angle of the scuta. 



Peduncle, wide at the summit, longer than the capi- 

 tulum ; calcified scales small, not arranged very regularly ; 

 flattened, spindle-shaped, rather far separated from each 

 other ; imbedded in membrane, so that even their summits 

 are rarely uncovered. The surface of the membrane is 

 thickly clothed with spines, which are strong, thick, 

 yellow, pointed, and furnished with large tubuli running 

 to the underlying corium. These spines are arranged in 

 groups of from three or four, to five or six. Besides these 

 larger spines, the whole surface is villose with very 

 minute colourless spines, not above ^th of the length of 

 the larger ones. The surface of attachment is broad. 

 This species, not being symmetrically attached to a coral- 

 line, the peduncle does not curve, as in most of the other 

 species, towards the rostrum. 



The capitulum is above half an inch in length. 



Mouth. — The labrum is much produced downwards, 

 but yet the mouth is not very far distant from the adduc- 

 tor muscle : the upper part is builate, forming a small 

 overhanging point, and in longitudinal diameter equals 

 the rest of the mouth. Palpi blunt. 



Mandibles with four teeth, strong, short, thick, the 

 second tooth much smaller than the others ; inferior angle 

 broad, pectinated. 



Maxilla with a long, rather sinuous edge, which, near 

 the inferior angle, has a narrow projecting point, bearing 

 rather finer spines ; there is, also, apparently, a very 

 minute tuft of small spines close under the two large 

 upper spines : there are, altogether, about twenty pair of 

 spines, without counting the smaller ones. 



