PLATE IX. 



Fig. I. Carirtella sfeciosa. Transverse section through head in front of brain 

 showing, particularly, position of enormously developed cephalic glands 

 (^cgl) and arrangement of cephalic nerves («!')• ^^^ cephalic glands 

 are thickly placed both above and below the cephalic blood lacunae [bl), 

 as well as around the rhynchodseum {rk). The secretion from many of 

 these glands is discharged near the lateral margins as indicated {dgl). 

 Between the longitudinal and oblique muscles {Im), which lie in the 

 deeper parts of the head, and the circular fibrous layer {cm), composed of 

 muscles and connective tissue fibers underlying the integument (« ), are 

 numerous and very massive nerves {nv) which supply the head regions 

 in front of the brain. The broad indentation on the ventral margin has 

 no relation to the mouth, which lies much farther back. Other reference 

 letters are explained above (p. 83). A small individual. ( X45)- 



2. Cariiiella speciosa. Transverse, but somewhat oblique, section through 

 head in region of brain. On the right of the section the brain [dg and vg) 

 lies directly beneath the circular fibers [cm). External to the brain, and 

 lying among the bases of the integumental cells, is the highly specialized 

 cerebral sense organ [cso), connected with the dorsal ganglion [dg) by 

 several small nerves (sn). The cerebral sense organ shows a conspicu- 

 ous central canal. The rhynchodseum {rh) has lost its fringe of gland 

 cells, these being limited to the regions anterior to it. The outer por- 

 tion of the circular layer (c;«) constitutes the basement membrane of the 

 integument. In the region of the brain the circular layer splits into two 

 sheets, one passing external to the brain and the other [ijl) internal. 

 Other reference letters as above. A large specimen. ( X25). 



3. Cariiiella speciosa. Transverse section through nephridial region show- 

 ing positions, and one of the openings, of the nephridial canals. The 

 lateral blood lacuna [bv) and the nephridial canal {nep) lie embedded in 

 a band of loose connective tissue on each side. The opening of one of 

 the efferent nephridial ducts {nd) is seen on the right of the drawing. 

 Other reference letters as indicated above. (X25). 



(102) 



