7G BALAN1D.E. 



three to five teeth ; the lower point or angle is generally 

 pectinated. In Coronnla and its close allies, there are some 

 small teeth intermediate between the four or five main 

 teeth ; and in these genera, though members of the sub- 

 family Balaninae, the lower teeth exhibit only rudiments of 

 being laterally double.* The Maxilla sometimes have a 

 notch under the upper large pair of spines, and in Octomeris 

 brunnea there is a double notch : in many species of Bala- 

 nus, the inferior corner stands up like a step (PL 26, 

 fig. 7, a) : in many other genera and species, the whole edge 

 is straight. In all, or almost all cases, the row of spines on 

 the middle portion is double. The Outer Maxillce are always 

 bilobed on their inner faces, and are clothed with bristles. 

 On all the gnathites, the bristles are often doubly serrated. 



Muscles and functions of the Gnathites, and their con- 

 fluence. — The outer maxillae appear at first like a deeply- 

 lobed lower lip, for they reach over almost to the labrum 

 (PL 26, fig. 1), and thus partially cover the other organs; 

 they are separately capable of a strong and rapid, to and fro 

 movement, by which no doubt they sweep any prey, en- 

 tangled by the cirri, towards the other gnathites. Each 

 outer maxilla is furnished with a pair of muscles, apparently 

 a flexor and extensor ; there is also a little muscle between 

 the two maxillae, I presume for the purpose of bringing 

 them together. The outer and inner maxilla? generally 

 stand close together, and in several genera a little way 

 apart, from the mandibles ; but there is no trace of any 

 labium or true lower lip, bounding the mandibles and 

 orifice of the oesophagus. The outer and inner maxillae and 

 mandibles are not opposed in pairs to each other, but 

 against the thickened inner fold of the labrum ; almost in 

 the same manner as the posterior pairs of cirri are not 

 opposed one to the other, but to the mouth. 



I have described pretty accurately the muscles of the 



* M. Martin St. Ange describes, in his 'Memoire sur l'Organisation des 

 Cirripedes,' pp. 15 and 32, "une petite langue" in the mouth of Lepas; but I 

 may venture to assert that such does not exist ; it is merely the point of union 

 between the outer maxillse. M. St. Ange, in his comparison of the mouth of 

 Lepas with that of Phyllosoma, compares the mandible of the latter with the 

 palpus of Lepas ; the first maxilla of Phyllosoma with the mandible of Lepas; 

 ana so on witli the other glial hites. 



