SEA-FISHERIES LABORATORY. 197 



The other appendages are all on the ventral surface. 

 The first are the antennae. These consist each of two 

 joints, a short stout basal one, and an apical one in the 

 form of a strong prehensile claw. The antennae are used 

 to assist the second maxillipedes in grasping.* The apex 

 of the claw projects into a small cup in front of the first 

 maxillae. 



The mandibles are enclosed in the suctorial mouth 

 (Plate II., fig. 8). They are stylet shaped, and composed 

 of four joints. The apical joint of each mandible is 

 flattened, curved inwardly, and serrated on its inner 

 margin. There is no mandibular palp. 



The appendages described here as the first maxillae are 

 given that name with some doubt. The pelagic Copepoda 

 have only one pair of maxillae, which correspond to the 

 second pair in this memoir. The identification of the 

 appendages now to be described as maxillae is based upon 

 the fact that they are innervated by a nerve from the sub- 

 cesophageal ganglion that has its origin just anterior to 

 the nerve supplying the maxillae proper. The first maxillae 

 consist of one joint which is considerably swollen at the 

 base, and tapers to a sharp point at the apex, forming as a 

 whole a curved claw. Two minute setae are attached to 

 the basal part, and probably represent the exopodite or 

 palp. These appendages are situated near the lateral 

 margins, and slightly posterior to the base of the antennae. 



The second maxillae are placed at the sides of the 

 mouth, and consist of a single joint, robust at the base 

 and dividing into two slightly curved teeth at the apex, 

 representing the exopodite. There is a distinct endo- 

 podite, with two setae at its apex, attached to the base of 

 the anterior surface of the exopodite. The second maxillae 



* Baird (op. cit. p. 263) describes these organs as the first pair of 

 footjaws. 



