192 DR. R. W. SHUFELDT ON [Apr. 1 , 



that exactly corresponds to this. It occurs upon the flexor aspect 

 of the lejr, and arises from the end of the fibula, close to the origin 

 of the flexor accessorius, and as a strong little bunch of fibres it 

 passes directly across to the bone representing the proximal tarsal 

 row, and is inserted thereupon, on its proximal surface. 



11.5. Abductor hallucis. — A small muscle that arises, tendinous, 

 from the distal surface of the consolidated bone of the first row, 

 and passing forwards is inserted into the proximal phalanx of the 

 hallux at its base. Mivart found this same muscle present in 

 V«««(P-Z. S. 1867, p. 797). 



116. Flexor minimi digiti. — Decidedly more inconspicuous tlian 

 the last, this muscle arises from the same bone upon the fibular side 

 of the foot, and passing forwards it makes a similar insertion into 

 the base of the proximal phalanx of the little or outer toe. 



117. Adductores digitorum. — Deep to all the plantar muscles 

 thus far described, this set consists of three flat, carneous, little 

 strips which are superficial to the interossei. They have a common 

 origin from the bone representing the first tarsal row, and, radiating 

 forwards over the sole of the foot as three distinct fasciculi, they 

 become inserted in their proper order into the bases of the proximal 

 phalanges of the second, third, and fourth toes, on the fibular side 

 in each case. 



118. Interossei plantares pedis. — Differing from these muscles in 

 the manus, the interossei of the plantar region are more numerous 

 than those of the palm, while those of the dorsum are less so. Their 

 origin and insertion, however, are essentially the same. There seem 

 to be five of these fasciculi present in the sole of the foot of Helo- 

 derma — three central ones, and one each to the inner side of the 

 outer toe and hallux. 



119. Interossei dorsales pedis do not seem to exceed three in 

 number, and they are devoted to the three middle digits. They are 

 disposed much as we find them in the hand. 



Mivart found interossei muscles also present in the pes oi Iguana 

 tuherculata, but the additional layer of fasciculi that he there 

 describes, I take to be my Adductores digitorum (see P. Z. S. 1867, 

 p. 797). 



I find no muscles present in the pelvic limb of Ileloderma sus- 

 pectum other than those I have described above. 



IV. On an Examination of the Contained Organs of 



THE CcELOM. 



Cutting open the body-cavity by a median, abdominal incision, 

 we at once bring into view the various organs that it harbours. It 

 will be seen that these are covered by the reflected layer of th 

 peritoneum, which in Helodenna is almost perfectly colourless, and 

 being very thin can hardly be said to obscure the viscera from our 

 view at all. This peritoneal layer differs from that membrane as we 

 find it in Iguana and Lacerta, in that it is not deeply pigmented 

 posteriorly and colourless anteriorly, as may be inferred from what 

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