PLATE IV. 



Figs. 33 — 36. • — C. Icinnseni. 

 Fig- n- — C. gracilis. 

 Figs. 38 — 40. — C. sibogae. 

 F'igs. 41, 42. — C. dodecalophus. 



F^isj. 33. C. levinseni. — Sagittal section of an old zooid, reconstructed from several sections. The proboscis 

 (/.) is turned at right angles to the left of the specimen, so that its lateral parts are seen on the 

 anterior and posterior sides. The first five arms of the left side (Z,. / — 5) are seen. The five 

 unnumbered arms belong to the right side. The ovaries of this specimen are very small. The 

 right ovary yov.) with its pigmented duct, is represented, partially overlapped by the dorsal vessel 

 [d.v.) and the rectum (r.). 



Fig. 34. C. levinseni. — Median sagittal section of another zooid, tlraun from a single section with the 

 exception of part of the epithelium of the lower lip. The difference between this figure and fig. ^t, 

 is probably due to contraction of the longitudinal muscles. The anus (an.) is widely open, as a 

 large mass of faeces is being discharged to the exterior. The course of the notochord {nc/i.) is 

 indicated from the adjacent sections. The wall of the intestine is cut somewhat tangentially, so 

 that one of its folds subdivides its lumen: the alimentary canal is not cut medianly at its principal 

 bend. The proboscis {/>.) has its normal position, but its stalk is greatly contracted, as indicated 

 by the folds of its wall. 



Fig. 35. C. levinseni. - — A section to the right of the middle line of the same individual. A lobe [op.) of 

 the operculum is seen disconnected from the basal part of the organ. The oral muscle (or. in.) is 

 seen both dorsally and vcntrally to the mouth (/«.). 



Fig. 36. C. levinseni. — A still more lateral section of the same individual: — ins, anterior longitudinal 

 muscles of metasome, inserted into septum -\^; c. c, edge of collar-canal; g. s., wall of gill-slit ; 

 p.p., internal opening of proboscis-pore. 



F'ig. 37. C. gracilis. — Median sagittal section, combined from the sections of a nearly sagittal series. 

 The notochord is not well shewn in this individual. 



F'ig. 38. C. sibogae. — Median sagittal section of the alimentary canal of a neuter. The bend of the canal 

 is injured, but its arrangement, as indicated by the neighbouring sections, is shewn by dotted lines. 



Fig. 39. C. sibogae. — Part of a sagittal section of a neuter. The strongly marked epidermic thickening (y) 

 behind the central nervous system (c. n. s.) is obviously ciliated, and probably has a nerve-layer 

 at its base. The muscles are not indicated. Part of the h)-popharyngeal groove is seen, and is 

 marked pk. The upper lip is somewhat broken. 



Fig. 40. C. sibogae. — Side view of an entire neuter individual. The anterior part of the zooid is lost, 

 but the operculum (op.) is entire. 



Fig. 41. C. dodecalophus. — Combined from three sections of the series to which fig. 42 belongs; to shew 

 the relations of the muscles (ms) of the metasome to septum -/,, to the collar-canal {c.c.) which is 

 cut tangentially, to the gill-slit (g.s.) and to the origin of the oral muscle (or. in.): — • /■/• internal 

 opening of proboscis-pore; l.n. origin of lateral nerve. 



Fig. 42. C. dodecalophus. — Median sagittal section of the same specimen, drawn from a single section. 

 The notochord is not cut medianly, but its opening into the pharyngeal diverticulum {div.) is 

 seen in the middle of the glandular area in the anterior wall of that cavity. 



[All the figures mere dratvn zuith Zeiss C Obj., and ivere then reduced '/oj. 



