BY C 1). GII.IJKS AND E1>NA F. VEBERDY. 5ft 



specimen a hair was inserted from the dorsal opening, and 

 passed anteriorly ; it didn't travel completely through, 

 as evidently some obstruction was jDresent in the canal. 

 In the remaining specimen, the latter could be seen passing 

 from the anterior end to the crest, but while endeavouring 

 to insert a bristle into the passage,' a portion of the former 

 broke off and became firmly wedged in the cavity. The 

 opening of the crest is in the region of the middle third 

 of the distance along the' latter. In some urostyles the 

 foramina of the 10th spinal nerves were observed. 

 Apparently (a) both may be present ; {b) only one, or (c) 

 both may be absent. 



In the examiuatioii of the urostyles (for the neural 

 canals) and the vertebrae, the specimens first were placed 

 in a solution of sodium hydroxide. Care had to be taken 

 to avoid prol6nged 1)oiling, as this resulted in the destruc- 

 tion of the bone. 



Several variations of interest were observetl. In one 

 sacral vertebra the specimen was asymmetrical ; the 

 extremity of the left transverse process (the vertebra being 

 viewed from the ventral surface) was higher than the right, 

 and the right tu])erosit3' of the urostylar articulation w^as 

 malformed. Another vertebra, a second, was remarkable 

 in having the right transverse process (from the ventral 

 surface) directed anteriorly, Avliile the left was horizontal. 

 One of the vertebral columns examined showed a double 

 variation. The transverse processes of the eighth and 

 one of the ninth Avere dilated or fan-shaped. The remaining 

 one of the ninth was flattened but not dilated. Apparently 

 the two vertebra^ formed a species of double sacrum. 

 When viewed from the ventral surface the right transA erse 

 process of the eighth was larger than the left, but the 

 left of the ninth was larger than the right. In size, the 

 larger of the eighth was abovit equal to the hargei' of the 

 ninth. 



Our thanks are due to Dr. T. Harve}' Johnston, 

 Biology Dept.. University, for allowing us to use the 

 Biology Laboratory for tliis research ; we are also 

 indebted to him for kindly criticism and directing our 

 attention to important literature. 



