REPORT ON THE HOLOTHURIOIDEA. 167 



PLATE XLII. 



Lcetmogone ivyville-thomsoni, The'el. 

 Fig. 1. Transverse section of one of the ambulacra ; the outer layer of the integument 

 is removed, a, outer pigmentary layer of the ambulacral nerve ; b, inner 

 pigmentary layer of the ambulacral nerve ; c, thick yellowish almost 

 structureless membrane separating the nerve from the ambulacral vessel ; 

 d, neural canal ; e, ambulacral vessel ; f, longitudinal muscular band ; 

 g, transversal muscular layer ; h, layer of connective tissue of the 

 integument ; k, small wheels ; I, spicula ; m, yellowish pigment ; n, 

 nerve ; p, violet pigment ; s, larger cells, 



Lcetmogone violacea, The'el. 

 „ 2. View of the ambulacral cavities of the pedicels, seen from the inner side of 

 the body-wall ; most of the integument is removed, a, radial ambulacral 

 vessel ; b, ambulacral cavities lying closely crowded side by side within 

 the ventral perisoma ; c, pointing out the position of the pedicels ; n, 

 ambulacral nerve ; m, longitudinal muscular band. 

 By mistake this figure is referred to Lcetmogone wyville-thomsoni on the plate, and 

 the lithographer has wrongly drawn the dotted line at m beyond the inner limit of the 

 muscular band. 



Ilyodosmon maculatus, The'el. 

 Fig. 3. Transverse section of the dorsal perisoma showing the dorsal ambulacra and 

 the processes which communicate with them ; twice the natural size, a, 

 ambulacral vesicles or ampullae ; b, dorsal processes ; c, cavities within the 

 perisoma. 

 ,, 4. View of the ambulacral cavities of the pedicels, seen from the outer side of 

 the body ; most of the integument is removed. a, radial ambulacral 

 vessel ; b, branched ambulacral cavities with their bases placed side by side ; 

 f, bases of the pedicels, the rest of them being cut off ; m, longitudinal 

 muscular bands. 



Kolga nana, Theel. 

 „ 5. View of a portion of the left ventral interambulacrum, seen from the inner 

 side, a, odd ambulacrum ; b, the left ventral lateral ambulacrum ; c, 

 ambulacral cavities of the pedicels ; d, auditory vesicles. 



Benthodytes sanguinolenta, n. sp. 

 „ 6. Diagrammatic side view of a minute dorsal process, highly magnified, a, 

 ambulacrum ; b, the integument ; c, process. 



