XVI LIST OF ILLUSTEATIONS. 



Pagf 



Tanais normani 36" 



Tanais normani. First gnathopod 369 



Tanais normani. First and second antennae 369 



Spongophora apicidentata, and terminal segment of abdomen of S. brunneipennis . 461 



Votes townsendi, side view 464 



Vates townsendi, top view 465 



Tomonotus ferruginosus, top view 470 



Mestobregma gracilipes, top view . 472 



HeUastus benjamini 475 



Young female of LejtPopJdheirus edwardsi, showing the fifth pair of swimming 



legs at the posterior corners of the genital segment 492 



Adult female of Cnligus mutabiUs, showing the body regions and the areas of 



the carapace 494 



The median sucker of Caligus rapax 495 



Ventral surface and appendages of an adult female Lepeophtheirus edwardsi. . . 498 



Ventral surface and ai)pendages of an adult male Lepfophlheirus edwardsi 499 



The second antenn;e and the first maxilhc of the adult Caligus boniio. Upper 



figure, the male; lower, the female 500 



Mouth parts of Lepeophtheb-us hrppoglossi 500 



Second antennae, first and second maxillae and mouth tube of adult Caligus 



rapax, highly magnified to show exact position, relations, and structure 501 



Ventral surface of the mouth tube of an adult Caligus curtus. (After Pickering 



and Dana) 502 



Ventral view of the mouth tube of Caligus rapax in a late chalimus stage 502 



Dorsal surface of the mouth tube Caligus rnpax in an advanced chalimus stage. . 503 



First maxilliped of Lepeophtheirus edwardsi 504 



The second maxillipeds of the adult Caligus boniio. Upper figure, the male, 



with a large bony plate on the basal joint; lower figure, the female 504 



First swimming leg of adult female Caligus bonito, ventral view 506 



Second swimming leg of adult female Caligus bonito, ventral surface 507 



Third swimming leg of adult female Caligus bonito, ventral view 508 



SectioiT of body wall of Lepeophtheirus pecloralis. ( After Claus) 510 



Longitudinal section of Lepeophtheirus showing relation of internal organs. 



(After A. Scott) 511 



The digestive system of Caligus rapax; chalimus fully grown 511 



Transverse section of Ijepeophtheirus in the region of the second ma'killipeds. 



( After A. Scott) 512 



Cross section of the genital segment of a Lepeophtheirus. (After A. Scott) 512 



Digestive glands in Lepeophtheinis. (After A. Scott) 513 



Posterior digestive glands of Caligus rapax 514 



Oblique muscles which operate the rectum in Caligus rapax during respiration. 517 



Musculature of a male Caligus curtus. (After Pickering and Dana) 518 



Musculature of a male Homoiotes paUiata 519 



Musculature of the second maxillipeds of Caligus rapax 520 



Nervous system of a Lepeophtheirus 521 



Nervous system of a Caligus 522 



Female reproductive organs of Caligus bonito 524 



Ovary of Caligus bonito enlarged 525 



Genital segment of Lepeophtheirus edwardsi just after the hatching of the eggs 



and the throwing off of the egg cases 525 



Genital segment of Caligus rapax 526 



Semen receptacles and vagina of a female Lepeophtheirus 527 



Sexual organs of a male Lepeophtheirus edwardsi 528 



