



FIG. 86. 



FIG. 90. 



IX fig.s 35 36, 37, 38. Fig. 8q represents the"roof pans of the skull with transverse lines having the same meaning as in Fig. 88 (see explanation under 

 I'l. XVli. fig. 59*. Pic. 82. Lateral viexvdalstbwiediDfiositeuartjditttr^. 8gC4 ( xapjKjs. 184. Composite head-kidney in a double mon- 

 FIG. 90.!' present in the angle between the twin heads of a cloubieiouble sitwsity, of the' r fyp.e i <ie'S<h<^a< d pjter4V'<;Ld 

 monster belo^g'ing to Class II., 1 ^.^'^^ of the i^Txv^ftft^jT^ glomerura^t^t's 1 "^' pr'ese'ii 

 brains at the medulla oblongata. Description on p. 17, divided into three chambers. 



brains at the medulla oblongata. Description on p. 

 and other references under PI. I. fig. 6. 



Utricle. 



An anteriorly placed semicircular canal. 



A posteriorly ,^ 



heail-lydney of a normal trou 



it rf v at! 



,:.- ' 



Glomerular tuft of ve: 

 Afferent/Vessel, 

 - Effere 



Capsul^of glomerulus.l 

 Corunjencement of VVoilj 

 i of Wolffian duofll 



divided into three chambers. 



O. Mesial chamber. 



FIG. 85. Head-kidney in a double monstrosity of same 

 general type as last, but here the glomeruli have not united 

 ether, though the adjacent halves of each give origin to 

 n-dycts-or only te a short Wind one-; -tittering 



/ Fits. 86 AT^B-S?. ftad-kidney glomer^ii of other two 



double monstrositie* showing a decree of duplicity greater 

 nlhat illustrated in Fig. 85. . A blind 1 sacculated tube 

 off from the middle compartment of the composite 

 lus and represents united adjacent Wolffian ducts. 



KlG. 93. 



H 



FIG. 91. 



FIG. 93. 



,. 91-93. Diagrams of the cartilagin ton and of the brain cavities in a double monster belonging to Class II., i.e. with union in the 



of the medulla. The numbered 'ti < nes are for the same purpose, and have the same meaning as in PI. XXI. hgs. 88-90. The general 



'lass II. lire given under PI. I. lip a under PI. XVII. fig. 61. XVIII. fig. 71. (xapprox. 15.) 



olfactory capsular can; 

 trabeculae cranii. 

 parachovdal cartilages. 



I.KTTKRING IN ALL THE FIGURES. 



//' 

 ' 



d on trabeculae in front of the two pituitary spaces. 

 t on parachordals behind the pituitary spaces and the tendon of 

 reel. oc. ext. 



^ 



outer and inner palato-ptei ygoids. 



,, ,, hyomandibulars. 



,, ,, periotic cartilages, 



in the two pituitary spaces, 

 outer and inner Medici's bars. 



,, hyoid arches. 



J. F. G. 



PL. XXI. 



