Royal Academy of Sciences of Paris. 155 



father ; we then call it a monster, but all the individuals which we 

 consider normal, would be monsters if considered in reference to 

 their original progenitors. 



Lusus Natures. On the 18th of April, a communication from M. 

 Leon Dufour, Corresponding Member of the Institut, was read to 

 the Academy. It contained a curious account of an anomalous 

 growth of hair in the region of the sacrum of a young man whom 

 he had recently had occasion to examine for the conscription. This 

 mass of hair perfectly resembled that of the head, both in length, 

 colour, and quality. The skin from which it sprung was as white 

 as the surrounding parts, thus preventing the possibility of the phe- 

 nomenon being referred to the class of defects known by the name of 

 moles, in which the colour of the skin is always dark, and the hair 

 coarse and short. M. Dufour characterises the case as falling 

 under that class of exceptions to the usual laws of organization 

 which are designated as rudiments, and considers it as presenting 

 the character common to several mammiferce, of having the lower 

 extremity of the vertebral column covered with long hair. The 

 young man in question did not present any extraordinary develope- 

 ment of the vertebrae of the coccyx, and may, therefore, be consi- 

 dered as complete an anomaly as the woman with four breasts and a 

 cow's tail, mentioned by Voltaire in his * Philosophical Dictionary.' 



On the 23d of May, M. Fabre handed to the Academy a foetus, 

 which had come to its full term, and even lived a quarter of an 

 hour, having but one eye placed in the centre of the brow, and ap- 

 pearing to result from the junction of two eyes closely united. 

 There was no external appearance of nose. 



Fossil Remains. At the meetings of the Academy, on the 2nd and 

 9th of May, M. Geoffrey St. Hilaire communicated various particu- 

 lars relative to some fossil remains discovered at Caen, which belong 

 to an animal named by him the ielco-squrus. He exhibited several 

 drawings of these fragments, and also the ventral and dorsal cara- 

 paces of the animal : the former differs from that of the crocodile, 

 which has no bony scales, whereas that of the fossil animal is com- 

 posed of strong bony pieces, while a plate, equally hard, and of 

 proportional dimensions, is under the throat, having, however, two 

 sloping cuts, to admit of the lateral movement of the head ; the latter 

 is composed of bony scales, placed over each other, nearly in the 

 same manner as those of the crocodile. From the peculiar organi- 

 zation of these animals, the learned professor concludes that they 

 could never have breathed in an atmosphere similar to that in which 

 we now live, but must have existed at a period anterior to the 

 crocodiles and other animals of that species. The teleo-saurus must 

 necessarily have been a marine animal, and must be referred to the 

 same period as the ichthyosauri, the gryphites, the nautili, and other 



