40 PEOF. M. M. HARTOG ON THE MORPHOLOGY OF CYCLOPS. 



the incomplete circular muscles in fascicles attached at the sides of the gut, and diverging 



towards the upper (and lower) median line; the striation is too marked, and the longitudinal 



fibres are omitted. E. 

 Fig. 4. Sagittal section (almost exactly median) through front of cephalon, showing relations of rostrum, 



epistoma, and labrum, oesophagus, and muscles of deglutition, brain with azygOs nerve and 



ganglion, eye, and nerve-cord. x 150 : C. 

 Fig. 5. Transverse section of maxillary region of male (slightly diagrammatized), and the anterior branches 



of the uterus, introduced from a corresponding section of a female, showing muscles of maxilla, 



position of entosternite with its suspensors, retractors of prcoral bar, nerve-cord, stomach, and 



pleural muscles, &c. x 150 : C. 

 Fig. 6. Horizontal section of front of cephalon of female, showing relations of mouth, &c., salivary glauds, 



and duct. x 150 : C. 

 Fig. 7. Left kidney of immature female, in natural position, from without, shaded to convey relations 



of its successive coils : 1, point at which it bends inwards (into ccelom ?) ; 2, commencement 



of duct, x 250 : D. 

 Fig. 8. From a transverse section in the region of the anterior maxillipeds, showing relations of kidney 



and duct : 1, 2 as in Fig. 7. x 125 : D. 

 Fig. 9. Left kidney of NaupUus, 2nd stage, in situ, from below, with its termination (opening ?) on base 



of antenna, and its other end in a mass of protoplasm in the body, x 525 : J. 

 Fig. 10. Series of maxilla; from various Copepoda, to show transitional forms from biramous condition to 



that of the Phyllopod (copied by kind permission from Brady's 'British Copepoda') : — 



a. Calanus finmarchicus, Gunner ; b. Metridia armata, Boeck ; c. Pseudocalanus armatus, 



Boeck ; d. Pontella JVollastoni, Lubbock ; e. Pseudocy clops oblusatus, Brady and Robertson ; 



/. Parapontella brevicornis, Lubbock; g. Notodelphis agilis, Thorcll; /*. Rubertsonia tenuis, 



Brady and Robertson. 



Plate IV. 



Fig. 1. Sagittal section o anterior part of nerve- cord, traversed by retractors of preoral bar. x 375 : E. 

 Fig. 2. Horizontal section of nerve-cord in region of first and second maxilla;, showing transverse fibres, 



slightly deeper on left side, x 375 : E. 

 Fig. 3. Superficial view of brain, from a dissection (osmic acid, cochineal, oil of cloves), with origin of 



nerve to left antennule, forming a lateral lobe, x 250 : D. 

 Fig. 4. Sagittal section of brain and eye to left of median line, showing left superior frontal nerve. 



x 250 : D. 

 Fig. 5. Sagittal section of eye, nearly median, x 525 : J. 

 Fig. G. Slightly oblicme section of eye. x 375 : E. 

 Fig. 7. Horizontal section of inferior (median) ocellus, x 375 : E. 

 Fig. 8. Dissection (after gold chloride) of front of brain and eye. x 250 : D. 

 Fig. 9. Transverse section of nerve-cord in posterior region of first maxillae, x 375 : E. 

 Fig. 9 a. Section at level of posterior maxillipeds ; all nerve-cells alone indicated, x 150 : D. 

 Fig. 10. Portion of large nerve-trunk laid open by razor, and showing nucleoid granules. x 525 : J. 

 Fig. 11. Expansion of a large nerve (sensory, below hypoderm). (From a transverse section.) 

 Fig. 12. Doyerian eminence, from same section as fig. 11. x 375 : E. 

 Fig. 13. A nucleus from posterior end of testis (rhachis) : b, dividing nuclei from a little further on, one 



showing the diaster stage, with spindle of achromatin fibres ; c, male ova, or spermatosporcs 



from about middle of testis ; d, male ova, with dividing nuclei, from a little further on. (All 



these taken from a dissection treated as in fig. 3.) x 1050 : J. 

 Fig. 14. Expulsive bodies from a crushed seminal vesicle, slightly swollen (Draper's ink, glycerine), 



x 750 : E. 



