176 ANELASMA SQUALICOLA. 



In other cirripedes, the mandibles alone seem to force the 

 prey down the oesophagus ; but here, the mandibles and 

 maxillae equally stand over the orifice, and their adjoining 

 spinose faces and edges, seem excellently adapted to force, 

 by their united action, any minute living creature down 

 the passage. 



The Outer Maxilla are almost in as rudimentary a 

 condition as the palpi ; they are quite spineless ; viewed 

 externally, they appear like two smooth, blunt, very 

 minute projecting points ; but viewed internally, the 

 membrane forming the supra-cesophageal hollow seems to 

 be united actually to their tips, so that they do not project 

 at all. I was surprised to find that the longitudinal 

 muscles going to these organs were developed, in pro- 

 portion to the other muscles, quite as fully as in ordinary 

 cirripedes: hence, these two little outer maxillae, no doubt, 

 serve as an under lip, and possess the usual backward 

 and forward movement. 



The surface of the probosciformed mouth facing the 

 first pair of cirri, has a deep central longitudinal fold, and 

 rather more than half-way down, a transverse fold ; just 

 above this latter fold, and therefore quite below the outer 

 maxillae themselves, the two olfactory orifices are seated ; 

 these are unusually large, and the sack into which they 

 lead, is most unusually large and deep. In this Cirripede, 

 I was first enabled to observe that the membrane lining 

 the sack is tubular, and open at the bottom. 



Cirri. — There are, as usual, six pair, and not of very 

 small size ; they have a shapeless and rudimentary ap- 

 pearance ; they are coloured, like the rest of the body, 

 blackish purple: they are quite spineless, and not articu- 

 lated, but their anterior faces are either obscurely or very 

 plainly lobed, so that in some (for instance in the third 

 pair, PI. IV, fig. 6), nine or ten prominent steps could be 

 counted, manifestly representing so many segments. The 

 rami are equal in length in the first pair, and slightly 

 unequal in the second and third pair; these two latter 

 are longer than either the first or three posterior pair. 



