Transactions and proceedings and report of the Philosophical Society of Adelaide, South Australia . conditionno evidences of the adaptation of the mouth to a nipple. Thelimbs are short and stout, the free portion of the fore limbbeing considerably longer than the corresponding portion ofthe hind limb. The manus and pes are of peculiar interest. In the manus the enormous, and early, specialization ofdigits 3 and 4 is remarkable. It is to be noted that, although 39 the digital specialization lias proceeded so far, the manus hasnot undergone the adult folding which makes the determin-ation of the
Transactions and proceedings and report of the Philosophical Society of Adelaide, South Australia . conditionno evidences of the adaptation of the mouth to a nipple. Thelimbs are short and stout, the free portion of the fore limbbeing considerably longer than the corresponding portion ofthe hind limb. The manus and pes are of peculiar interest. In the manus the enormous, and early, specialization ofdigits 3 and 4 is remarkable. It is to be noted that, although 39 the digital specialization lias proceeded so far, the manus hasnot undergone the adult folding which makes the determin-ation of the different elements a matter of some little diffi-culty. It is well known that in his original communication(1891) Sir Edward Stirling designated the specialized digits; as 4th and 5th, and assumed that the small digits were the1st, 2nd, and 3rd. In the extended description published inthe same year this error was noted and corrected, and correctfigures were published. Despite this, Lucas and Le Souef(1909) speak of the edge of the large triangular nail of thefifth digit being used for Fig. lateral view of the caudal region. In the embryo the 1st, 2nd, and 5th digits of the manusare represented by mere tubercles. It is a very remarkablething that the manus should attain one of its greatestpeculiarities by what is essentially an opposition of the 1stand 2nd digits to the 3rd, 4th, and 5th, such as exists, forinstance, in Phascolaictos. The pes is short and spade-like, the digits ranged in veryprimitive fashion, save that the 2nd is very slightly inadvance of the 3rd. The tail, so far, presents- none of its adult external genitalia reveal to external examination onlya raised cloacal margin from which protrudes a genitaltubercle. No trace of a pouch rudiment, nor of an umbilicalsite are visible externally. 40 Notes on Some Western Australian chitons (POLYPLACOPHORA), WITH ADDITIONS TO THE FAUNA and the Description of a New Spe
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Keywords: ., bookcentury1800, bookdecade1870, booksubjectscience, bookyear1878
