Arteries in Monsters of the Dicephalus Group 445 



and Hirst and Piersol [page 147, Fig. 72]. The human face is so 

 short as compared with the elongated faces of the monsters under 

 consideration that at first sight, perhaps, the similarity is not striking, 

 but a moment's consideration will verify the likeness. In my specimen 

 the two snouts are quite separate, the distance between their tips being 

 85 mm. Both appear normal, well developed and of equal size. Two 

 normal external ears are present, but there is no indication of a median 

 pinna. Within the mouth cavity of each component is a fully developed 

 tongue and several teeth. Protruding from the inner lateral side of 

 the mouth of each component is a short papilla-like protuberance which 

 curves slightly upward over the upper jaw [see Plate I, Fig. 1, c.].° 

 This minor deformity is symmetrical, howeveir, in each component 

 with reference to the entire organism, being on the inner lateral side 

 of each componental snout and gTOwing from the same region of the 

 roof of each mouth. The characteristic throat warts appear here as two 

 about IS mm. apart, and equidistant from the median axis of the body. 

 The two outer eyes are also normal, the eyelids being perfectly formed, 

 even to the presence of eyelashes. The median eye is made up of a 

 double eyeball lying within a single socket. The eyelids are fringed 

 with lashes and form an inverted heart-shaped opening, which with 

 its associated parts is perfectly bilateral. The median eye socket is 

 nearly spherical in shape, being 19 mm, in diameter measured trans- 

 versely across the head, and 20 mm. in diameter measured in the direc- 

 tion of the median axis of the monster. Contiguous with the socket 

 posteriorly and separated from it only by a thin septum of bone, is a 

 curious heart-shaped cavity with the apex directed backward. This 

 cavity lies between the two outer eye orbits and was filled with a pro- 

 trusive mass of pathological brain tissue. Its bony floor and walls are 

 perforated with foramina for the passage of nerves. It measures 23 

 mm. in diameter across its broadest part, and 25 mm. along its median 

 axis. This is plainly a deformed cranial cavity, and the everted brain 

 thus represents an actual deformation, Avhich must have taken place 

 in an early embryonic stage. It forms an exception, however, to the 

 greater part of the organism, but is at the same time a deformity that 

 i:^ apt to be associated with such monsters; and all cosmobia are secon- 

 darily subject to deformities. 



'The terms inner lateral and outer lateral, inner side and outer side are 

 used with reference to the two sides of the components. Median and lateral 

 refer to the whole organism treated as a single symmetrical solid. 



