INVERTEBRATA, CRYPTOGAMIA, MICROSCOPY^ ETC. 815 



body superficially into two unequal halves, being seldom wanting. It 

 shows an extraordinary resistance to the action of reagents, even hydro- 

 chloric and nitric acids merely hardening and rendering it more 

 transparent ! Its substance is greyish and granular, more transparent 

 towards the surface, where it is limited by a tough, flexible, refriugent 

 layer, not separable from it, and from '001- "002 mm. in thickness. 

 The only organized contents consist of minute granules, which have 

 no resemblance to trichocysts. Buds (c, h) bearing superficial protu- 

 berances (j) are produced ; their tissues are directly continued from 

 those of the parent. Tlie tentacle is inserted in the groove or the 

 portion furthest from the pedicle if tliat is not present ; the cuticle 

 of the body is continued over it, being wrinkled (d) when it contracts, 

 and also forms a distinct band in the centre of the tentacle ; that part 



of large cilia ; c, non-contractile discoid portion of the body with the pultiatilo 

 vesicle ; d, lower crown of tine locomotor cilia. 



Fig. 8. — Lower concave face of the same, surronnded by the crown of loco- 

 motor cilia, d, and occupied by the indLUted wheel-like organ. 



Fig. 9. — Podophnja Lynf/hi/ci Ehr., front view, a, the insertion of the pedicle, 

 ab ; c, transparent theca, the margin of which extends beyond the granular sub- 

 stance of the body — the latter shows a pulsatile vesicle and hyaline expansions. 



Fig. 10. — J'odophrya witlj four gemmae, e, about one quarter developed. 



Fig. 11. — Large J'odophrya with eight gemniffl, e, at the close of their develop- 

 ment, the extended filaments not having completely disappeared. The margin 

 of the internal concave face of tlie gemm® has also short mobile cilia. In each 

 gemma are one, two, or sometimes three pulsatile vesicles. 



Fig. 12. — Phases of the passage of a gemma to the state of a fixed pedicellate 

 PodophrJ/a. 



a, gemma becoming fixed, still provided with cilia, ?, and with a verrucoso 

 dorsal face. 



b, tlie same, a quarter of an hour later, attached directly by its lower face and 

 not showing any cilia. 



r, tlie same, twelve or fifteen minutes later, elevating its two extremities, and 

 the dorsal face emitting some pale and short filaments. 



d, e, the same, at the end of two successive quarters of an hour. 



/, the same, fifteen minutes later, having already assumed the general form of 

 the adult ami ^^till directly fixed to the Sertularia by the narrow portion, y, where 

 the pedicle is inserteii. 



g, the same, about twenty minutes later, with longer and more numerous 

 filaments, some already pointed, A short pedicle, /t, is developed, and the 

 body resembles still more nearly the adult. 



/i, the same, half an hriur later, difteiing from the adult only by the shortness 

 of the pedicle, /, and the few coloured granules of the body. 



Fi(i. 13. — J'odophri/a witii the body, r, reduced to small (liraensions after the loss 

 of the gemma) and recommencing to throw out filaments, still short and blunt, c. 



Fio. 14. — Poduj'hri/a, with a non-ciliated external gemma, /, and a bundle of 

 short filaments or blunted suckers, h. a, b, pedicle. 



Fig. 15. — Variety of Codonosiya botrytis Stein ex Ehrenberg, with four rigid 

 cirrhi,/, instead of a collar. 



a, enlargement of the base of the pedicle attached to stationary bodies in the 

 water; '», thickening of the summit of the jieilicle which bears the bddy of each 

 animal ; e, individual with the rigi<l cirrhi united by a mt nibrane forming a 

 collar ; /, the four stitV cirrhi inserted round the njiper portion of the animal so as 

 to resemble hyaline opercula; i, thin circular membrane in the form of a slightly 

 raised cuj) inserted on the hyaline operculum round the ba.se of the llagellum, 

 alternately contracting and dilating ; j, the tlageiliun, four to six times as long as 

 the body, and as large at its termination, which is blunt, as at its iusortiou in 

 tho miiidh^ of the hyaline oiKTCiilar summit. 



[In tho lettering of the I'lates for "Lyngbei" rend " Lyngbyei," and for 

 " Conodosiga" read " Codonosiga."] 



