LIST OF ILLUSTRATIONS. XV 



Page. 

 Transverse section through third thoracic segment of Ergasilus centrarchidarum. 

 eg, cement gland; g, ganglion of third swimming legs; i, intestine; Im, longi- 

 tudinal muscles; m, dorso- ventral muscles of third legs; n, nerve of third leg; 



sr, semen receptacle 297 



Dorsal "view of carapace of Ergasilus centrarchidarum, showing position of first 



two egg cells that issue from the ovary 299 



The first uterine processes forming posteriorly through the first thorax segment. . 299 

 The second uterine processes forming anteriorly in the head ; posteriorly can be 



seen the oviducts connected with the first uterine processes 300 



The third and foiu-th oblique uterine processes, extending forward and down- 

 ward from the outer sides of the first processes. Anteriorly can be seen the 



fused ovary and posteriorly the cement glands 301 



Fully matured female of Ergasilus centrarchidarum, showing relative size and 



shape of completed processes in dorsal view 301 



The relative size and shape of completed processes as seen in ventral view 301 



The relative size and shape of completed processes as seen in lateral view 302 



Cement gland of Ergasilus centrarchidarum. a, dorsal view; b, longitudinal 



vertical section 302 



Genital segment of male Ergasilus chautauquaensis, showing sperm receptacles. 303 

 Mouth-parts of female Ergasilus centrarchidarum. lb, labium; md, mandible; 



md. p., mandibular palp; mx^, first maxilla; ma/^, second maxilla 311 



Mouth-parts of male Ergasilus chautauquaensis. lb, labium; md, mandible; 



mx\ first maxilla; mx^^, second maxilla; mxp, maxilliped 312 



Three successive stages in the growth of the egg cases of Ergasilus centrarchidarum, 



showing that the eggs ripen in groups and not singly 317 



Newly hatched nauplius of Ergasilus centrarchidarum, dorsal view 319 



First antenna of nauplius of Ergasilus centrarchidarum 319 



Second antenna of nauplius of Ergasilus centrarchidarum , 320 



Mandible of nauplius of Ergasilus centrarchidarum 320 



First metanauplius larva of Ergasilus centrarchidarum. The first maxillae in 



this figine are concealed beneath the mandibles 322 



Labrum of first metanauplius larva 323 



Second metanauplius just ready to molt into the first copepodid stage 324 



First antenna of second metanauplius larva 325 



Mandible of second metanauplius larva. The exopod is turned back in order to 



show more distinctly the endopod and the masticatory process 325 



Mouth-TpaxtBoilemale Bomolochus teres. Za, labrum; Zft, labium; mc?, mandible.; 



vix^, first maxilla; mx^^, second maxilla; nixp, maxilliped 350 



Mouth-parts of male Bomolochus solex. an" , second antenna; la, labrum; md, 

 mandible; mxf , first maxilla; mxf^, second maxilla; mxp, maxillipeds; p, 



paragnaths 351 



Mouth-parts of female Tseniacanthusalbidus. an^^, second antennae; la, labium; 

 md, mandible; m. h., maxillary hook; mxf , first maxilla; mxf' , second max- 

 illa; mxp, maxillipeds 382 



Part of ventral side of thorax of Peneus seti/erus with bases of legs III, IV, V, S, 



shelf; Sc, scales, forming boundaries of the simple thelycum 421 



Longitudinal median section of thelycum of Peneus setiferus, ventral surface 



above. S, shelf; Sc, scale 421 



Sm'face view of thelycum and adjacent parts of thorax of Peneus brasiliensis. 

 ["^V and V bases of left fourth and fifth thoracic legs; S, base of shelf-bearing 



spine ; Sc, closed scale 422 



Cross section of thelycum of a young Peneus brasiliensis, showing scales right 

 and left 423 



