432 DR W. CARMICHAEL M'LNTOSH ON THE STRUCTURE OF THE 



°' , , ' > Hooks of Amage. x 700 diameters. 



Plate XIV. 



Fig. 1. Ovum of Pol la involuta, Van Ben., immediately after deposition. x 350 diameters. 



2. Ovum of the same species about the 10th day, showing the ciliated embryo revolving therein. 



x 350 diameters. 



3. Young of Cephalothrix filiformis shortly after extrusion from the egg. x 350 diameters. 



4. A young specimen of Cephalothrix, two days older than that shown in fig. 3 ; a, mouth ; b, 

 granules of digestive cavity. x 210 diameters. 



5. A specimen about three days older than the foregoing (fig. 4). x 210 diameters. 



6. Young Polia involute!, extruded from the body of the adult under pressure. It has the same 

 appearance when originating in a free ovum. x 350 diameters. 



7. Young C. filiformis, after shedding the long anterior whip of cilia, but having the lateral 

 tufts (c) and eyes; a, mouth; b, granules of digestive cavity. x 210 diameters. 



8. Transverse section through the proboscis of IAneus longissimus. x 55 diameters. 



9. Magnified view of the ganglionic region of a large Ommatoplea alba, in which a parasitic 

 ovum (//) lay imbedded in a granular lobulated mass (2/). 



... 10. Parasite extruded from capsule ; a, opaque cellular and granular mass ; b, ventral disc ; <-, 

 oral disc ; d, oesophageal bulb ; e, alimentary caeca ; / and g, large circular granular 

 bodies. 



... 11. Transverse section through the body of a large Meckelia .annulata. x 55 diameters. 



... 12. Head aud proboscis (a) of a remarkable variety of Meckelia, brought from Shetland (Balta) 

 by Mr Gwyn Jeffreys ; 6, curiously frilled arrangement of the enlarged homologue of the 

 superior lip of the cephalic fissure ; w, prolapsus of textures from 'mouth. Magnified 

 under a lens. 



... 13. Hook of A iiijilinri'te artica, Mgrn. x 700 diameters. 



... 14. Hook of Amphicteis gunneri. x 700 diameters. 



... 15. Hook of Terebella, from the Hebrides. x 700 diameters. 



Plate XV. 



Fig. 1. Bristles of AmpMnome vagans ; a, bristle from the inferior lobe of foot; b, c, bristles of the 

 superior lobe. x 700 diameters. 

 2 a. Dorsal bristle of Lepidonotus pellucidus, Ehlers. x 700 diameters. 



2 b. Ventral bristle of the same species. x 700 diameters. 



3. Ventral bristle of Polynue longisctis, Grube. x 350 diameters. 



3 a. Tip of the dorsal cirrus of the same species. x 55 diameters. 



4. 1 Two of the characteristic bristles (with jointed tips) of Sthenelais dendrolepis, Clap. 



5. J x 350 diameters. 



6 - ) 



6 a. > Ventral bristles of Halosydna gelatinosa, Sars. x 180 diameters. 



6 b.) 



7. Ventral bristle of Ophiodromus vittatus, Sars., with short terminal process. x 700 

 diameters. 



8. Fragment of a bristle from the dorsal lobe of the same animal. x 700 diameters. 



9. Bristle of Notophyllum polynoides, CErst. x 420 diameters. 



9 a. Lateral view of the end of the shaft and its processes in the same bristle, x 700 diameters. 

 9 6. Profile view of the same. x 700 diameters. 



10. Bristles of the littoral form of Spheerosyllis Jiystrix, Claparede ; a, simple spine ; b, jointed 

 bristle. x 700 diameters. 



11. Jointed bristles of Autolytus pictus, Ehlers. x 700 diameters. 



12. Bristle of SylUs, resembling >S\ macrocera, Grube. x 700 diameters. 

 13 a. Fragment of the frontal bristle (of Siphonostoma buskii) represented in fig. 4 a, PI. XVI. 



x 350 diameters. 

 13 b. Piece of a corresponding bristle from Trophonia glauca, Malmgren. x 350 diameters. 



1 4. Hook from the rasp-like surface of Ammocliares ottonis, Grube. x 900 diameters. 



15. Hook of Terebella zostericola, (Erst. x 700 diameters. 



