114 



Fig. 10. Same part from Cuma arenosa. 

 11. Same part from Lamprops fasciata 



(dorsal view). 

 12. Same part from Pseudocuma cercaria 



(ventral view). 

 13. Same part from Campylaspis ruUcunda 



(ventral view). 



PL LXVII. 



Internal Anatomy of Cumacea (continued). 



Fig. 1. Anterior part of body together with 

 the first 3 caudal segments of a young 

 female specimen of Leucon Nasica, 

 viewed from left side. Internal organs 

 delineated within the bodj* in their 

 natural position. Lettering as in fig. 

 1 on the two preceding plates. 



2. Left ovarial sac of the same indi- 

 vidual, isolated and more highly 

 magnified. 



3. One of the ova contained in the sac 

 isolated. 



4. Ovarial sacs of a very young specimen 



of Diastylis hicifera, showing the small 



median connecting part. 



5. Egg-cell from same, highly magnified. 

 6. Epithelial cell. 



7. Anterior part of intestine with the 



liver-sacs from Leucon Nasica ; ventral 



view. 

 8. Same part from a male specimen of 



Leucon fulms. 

 9. Heart with pericardium from a male 



Diastyloid.es biplicata, as found by 



dissection of an alcoholic specimen ; 



left side-view. 



PL LXVIII. 



Internal Anatomy of Cumaeea (continued). 



Fig. 1. Anterior part of body together with 

 the first 3 caudal segments of an 

 adult male specimen of Leucon Nasica, 

 viewed from left side. t. testes ; 



remaining letters as in fig. 1 on the 

 3 preceding plates. 



2. Testes of same species isolted, together 

 with last pedigerous segment; ventral 

 view. 



3. Anterior part of one of the testes: 

 more highly magnified, exhibiting the 

 cereal lateral lobes. From the lower 

 ruptured end, the zoosperms are seen 

 protruding. 



4. A bundle of zoosperms still enveloped 

 by a thin membranous sheath. 



5. Another bundle, in which the envelope 

 has been cast off. 



6. A fully-developed zoosperm isolated. 



7, 8. Front part of 2 other zoosperms 

 from same species, highly magnified. 



Fig. 9, 10, 11. Zoosperms from Leucon fulvus. 

 12. One of the testes from an adult male 

 of Diastylis hicifera. 



13. Anterior part of same, more highly 

 magnified. 



14, 15, 16. Zoosperms from the same 



species. 

 17 20. Not yet fully developed zoosperms 



from a young ma!e of Diastylis luci- 



fera. 



21. Germinal cells of same specimen. 

 22. Zoosperm from Hemilamprops rosea. 



PI. LXIX. 



Development of Cumaeea. Diastylis hicifera. 



Fig. 1. Ovum still enveloped by a thin filmy 

 membrane, and exhibiting the coarsely 

 granular central yolk-mass and the 

 peripheric layer of clear cleavage-cells. 

 The latter has considerably increased 

 on one side, to form the ventral face 

 of the developing embryo. 



2, 3. Another ovum in a somewhat later 

 stage, represented in 2 different po- 

 sitions, to show the cruciate arrange- 

 ment of the central yolk-mass. 



4. Early stage of the embryo, exhibiting 

 the first intimations of the limbs, and 

 still enveloped by the chorion ; left 

 side-view. fl 1 . superior antenna;; 



a-, inferior a ..tennse ; M. mandibles ; 

 L. anterior lip: w 1 . anterior maxillae; 

 in", posterior maxillae; mp l . 1st pair 

 of maxillipeds; tnp^. 2nd pair of 

 maxillipeds ; -iHp*. 3rd pair of max- 

 illipeds; p l . p 4 . legs of 1st to 4th 

 pair; f. dorsal cleft. 



5. Embryo in a later stage, viewed from 

 left side. The chorion has been cast 

 off, whereby the 3 anterior pairs of 

 limbs have been set free, the others 

 being still enclosed in the larval skin. - 

 C. inferior edge of the developing cara- 

 pace; urp. uropoda; I. capsule imbed- 

 ded in the yolk-mass and forming the 

 first, indication of the liver; remaining 

 letters as in fig. 4. 



6. A still more developed embryo, in 

 which the larval skin has been cast 

 off, thus causing all the limbs to 

 be freely exposed; lateral view. - 

 0. developing eyes ; R. rostral plates 

 of carapace; br. cxp. exopodal parl 

 of the branchial apparatus; t. telson; 

 remaining letters as in fig. 5. 



,, 7. Same embryo viewed from the dorsal 

 face. 



8. Embryo in the immediately succeeding 

 stage, viewed from left side. The 

 dorsal curvature of the body has 

 changed to a pronounced ventral one, 



