962 DESCRIPTION OF THE EXGPvAYINGS. 



specimen, partially protruded from its tube, whicli is liere shown entire, x300. 2. Lim- 

 nias Ceratopliylli : the end is protruded beyond the smooth tube or sheath ; at e is the 

 projecting chin. 3. Notommata aurita, viewed laterally, contracted : it exhibits the oeso- 

 phageal head and jaws (b), the intestine, the large ovarium, the contractile sac below, the 

 gTape-like ganglionic mass in the head(^), and the tortuous vessels on each side, running 

 the length of the body. 4. The same animal extended and rotating ; the ear-like ciliated 

 appendage, whence the specific name, is seen on each side of the head. 4 a. The ciliated 

 lobes of the rotary organ ; b, the gizzard, with its jaws ; ff, the cerebral (?) mass ; k, glands 

 above the stomach; o, large matured egg in the ovary. 5. Notommata aurita, viewed 

 dorsally, the viscera omitted, to show the muscular system ; the transverse muscles are 

 seen at t, and the longitudinal, crossing them, at I ; the grape-like ganglionic mass 

 appears connected with special muscles, as also the gizzard, traced in dotted ovitlme, and 

 the telescopic-w^orking tail or foot (b) ; the looped band at the head (o) indicates the 

 tubular cavities in the head-mass. 6. The same animal, showing chiefly its water -vascular 

 system ; the large sac near the bottom of its cavity (v) is the contractile bladder, from 

 wliich proceed, on each side, convoluted tubes (tortuous vesicles) furnished with tremulous 

 respiratory tags, as near a ; the transverse muscular bands seen at f. 6 *. The dental 

 apparatus of the gizzard as seen in action. 7, 8. The male of Asplanchna priodonta: 

 7. s. V. ; 8. f. V, T^he cavity is seen occupied chiefly by the large testes in fig. 7 ; the 

 sperm-duct is represented opening externally at the pointed base. 9. The female of 

 Asplanchna prioclonta: at a are the gill-like fissures; a large oral cavity opens into a 

 narrow oesophagus, which ends below in a stomach. One of the strong longitudinal 

 muscles is displayed, also tortuous vessels and ciliated tags, with an ovary. 10, 11. The 

 jaws of the Asplanchna detached. 



PLATE XXXVII. (Eotatoria). 



Figure 1. Stephanoceros Eicliliornii : a, sheath ; b, pharynx ; c, proventriculus, or 

 crop ; d, maxillary head with jaws ; e, stomach with large glandular cells ; f, intestine or 

 rectum ; g, ovary with contained ova {g at pedicle indicates the longitudinal muscles in 

 that segment) ; it, respiratory canal and tags. 2. Ovary and the enveloping membranous 

 sac, or uterus, extending from it, containing ova in different stages of development: a, 

 stroma of ovary with inherent ova ; the darker segment probably indicates the position of a 

 winter ovuin developing ; b, ovum dividing ; c, ovum in wliicli division of yelk has been 

 several times repeated ; cl, an ovum in which the rude outlines of the embryo are distin- 

 guishable, the two eyes at d, and the sac with the so-called luinary concretion at k; f 

 points to the uterine or ovarian enveloping membrane. 3. A very young Stephanoceros. 

 4. An embryo of Stephanoceros immediately after its exit from the shell. 5. An ovum of 

 Lacinularia. 6. Another ovum of the same, its yelk in process of fission. 7. A portion 

 of the ovary of the same, with four contained ova. 8. An oviun of the same, in which 

 division has been repeated several times. 9. Another ovum, wherein fission has been 

 repeated until the yelk is broken up into a number of cells. 10. A yomig embryo of 

 Lacinularia immediately after its exit from the egg. 11. Another embryo, fm^ther developed. 



12. Termination of a tentacular process of Melicerta ringens, showing the piston-hke disc, 

 capable of retraction by a muscular band affixed to it, and surmounted by a brush of cilia. 



13. A view of the same process, with the brush of cilia extended. 14. The same, with the 

 cilia retracted. 15. An embryo of Melicerta ringens, wliich has attached itself and has 

 commenced the formation of its case or sheath. 16. An embryo of the same animal as it 

 appears when swimming freely. 17. Melicerta ringens, fully developed, with the lobes or 

 petals of its ciliary wreath {a) fully expanded ; b, uncini ; c, ciliated process, representing 

 a fifth lobe; dd, tentacula, as shown in figs. 12, 13. 14; e, jaws; g, lower or second 

 stomach ; h, intestine ; Jc, coloured globules ; I, suctorial end of pseudopodium ; on, muscles ; 

 o't, gland ; o, ovum. 18. Two muscular fasciculi, showing transverse markings. 19. 

 Lacinularia socialis : a, pharynx ; b, maxillag, or jaws ; c, muscular crop ; d, stomach ; 

 e, lower segment of stomach, terminating in a narrow rectum and anus at if; g, a glan- 

 dular (?) process ; h, ovary ; ?', respiratory canal ; k, pedicle (Huxley). 20. MaxilljB of 

 Lacinularia socialis. 21. Winter ovum in act of division. 22. Segmentation of a 

 portion of the ovary, of a different character from the rest, in process of forming a winter 

 ovum. 23. Maxillae of Melicerta ringens, in bulb. 24. Winter ovum of Lacinularia. 

 25. A portion of ovary of Notommata centrura : a, the homogeneous germinal spot ; b, the 

 clear areola around it ; c, yelk-matter. 26. Maxillte of Melicerta ringens. 27. Winter ovum 

 of Asplanchna Sieboldii treated witli solution of soda. 28. Winter ovum in its natural 

 state. 29. Male of Asplanchna Sieboldii, viewed from the abdominal surface : a a, the 

 anterior short arms ; b b, the posterior longer arms ; c, testis, or spermatic sac, filled xnih. 

 spermatozoa ; d, water- vascular canal. 30 a, b, c, d, e, f. The corpuscles of the preceding 



