LIST OF ILLUSTRATIONS. XV 



Pag-e. 



Border of sucking dink in Argulas anicricanus B-'U • 



Posterior maxillipeds A rguJus americanu.^ fi'^2 



Dorsal view of the heart of Argulas americnnvjc <i, ])aired lateral opeiiiugH; h, 



anterior opening of aorta; c, anterior; d, posterior ventral opening 632 



Side view of the heart of ^4 rguluK americarws 633 



The nervous system of A rgulux americanvs 633 



Sexual organs of female Argulus a)nerira))vx: o, ovary; u. r., (tviduct; s. ]>., 

 semen papill;e; s. r., semen receptacle; f. }>., tactile papilla' at the openings 



of the oviduct 634 



Semen receptacles and iy3i\A\\n^ oi Argulux iunencanux female: h. /. , basal loljcs 

 of posterior legs; s. d., ducts leading from the receptacles to the ])ai)ilUf; 



s. p., semen papilhe; «. ?•., semen receptacles; 1. p., tactile papilla' 635 



Sexual organs of m?i\e Argulus a mericanus: h. c, blind capsule; c. '/. , ejacula- 

 tory duct; s. r., semen visicle: /., testes; r. J., vas deferens; r. c, vas 



efferens 636 



Posterior legs and abd( )men of . I rgulus americanus 637 



Micro-photograph of egg string of Argulus americarnts, showing the jelly i>ro- 



tuberances and tlie larv;e partially developed 637 



An egg of A rgulus americanus approaching maturity 638 



Newly hatched larva? of Argulus americanus 639 



Free thorax and abdomen of Argulus americanus lar^'a 640 



First antennte of the newly hatched larva of Argulun ainenranux , . . . . 641 



Anterior maxilliped of the newly hatched A rgulus auiericanus 641 



Second maxilliped of tlie newly hatched larva f)f Argulus americunus 642 



First swimming leg of the newly hatched larva of Arg-ulus aiDericdnus 642 



Dorsal view of female Argulus versicolor 645 



Ventral view of female Argulus versicolor 646 



Detail of antennae of Argulus versicolor 646 



Sting and poison gland of Argulus versicolor: cli. r., chitin ril) of proboscis; </., 

 ducts of poison gland; g., poison gland; ut. m., mandible muscles; oe. m., 

 a>sophagus muscle; oe. ?//., side muscle of oesophagus; r. ///., retractor mus- 

 cle ; .s. , sting 647 



Chitin skeleton of the prol)oscis in Argulus versicolor 648 



Chitin ribs in the margin of the sucking disks of Argulus vcvsi<r>lor 648 



Posterior maxilliped of Argulus versicolor 648 



Scales on ventral surface of the i>osterior maxillipeds of Argulus versicolor 649 



Terminal joint of posterior maxilliped of ^Irgulus vers-icolor 649 



Dorsal surface of the anterior leg on the right side of Argulus versicolnr, show- 

 ing size and attachment of normal flagellum 649 



Three posterior pairs of legs in the male Argulus versicol(u- 650 



Basal joints of the two posterior legs of male Argulus vevsii-olov, seen from the 



ventral surface 650 



Dorsal surface of a female .Irgulus Iriliueata 652 



Ventral surface of a female Argulus trilineata 653 



First and second antenna' of .1 rgulus frilineato 054 



Posterior maxillipeds of ^irgulus trilineata 654 



One of the pigment spots on the dorsal surface of the free thorax of Argulus 



trilineata 655 



Abdomen of Sj))i;rrouui pvutiulun 660 



Idotea gracillima 662 



Abdomen of Idotea gradlliuui sin )wing variations 662 



Sifnidotea ritteri 664 



Head of {a) Sunidotva ritteri -awA of (//) S. consolidatu 664 



Proc, N. M. vol. xxvii — 03 ii 



