440 PERCY SLADEN TRUST EXPEDITION 



Tryon's supposition that this is a young form is borne out by the deUcacy and fragiUty 

 of the tissues but by nothing else. The condition of the arms and suckers and the 

 general appearance, which is peculiar and characteristic, do not suggest that it is young. 



It is very much to be regretted that only a single specimen was found, otherwise 

 some interesting anatomical characters might have been revealed. The branchial cavity 

 alone was opened and found to reveal at least one interesting feature. As far as the radula 

 is concerned there is nothing to separate it from a normal Polypus, but the single mandible 

 examined is somewhat peculiar. 



The hranchice occupy a peculiar position in the mantle cavity, being inserted into the 

 visceral mass at a remarkably high point, well up into the apex of the mantle cavity. In 

 form they are extremely long, flat and strap-like. 



The radula (Text-fig. 6) is normal. In the median tooth there appear to be two main 

 lateral cusps, the separation and approximation of which in different teeth give rise to 

 two main types indicated in the figure. 



Fig. 6. Polypus VENUSTUs; Radula. Cam. 6 oc. x 6 obj. Reich. 



The lower mandible alone was examined, the upper member of the pair being somewhat 

 damaged. It is peculiar in exhibiting an excessively deep notch and a very small anterior 

 lamina. 



Distribution previously hnown : "Algiers: Goree." 



6. Polypus granulatus Lamarck. Mem. Soc. Hist. Nat. Paris, i. p. 20, 1799. 



One example, about one-third grown, $ (?), from Amirante, 22 — 85 fathoms (1402). 

 I share Dr Hoyle's view (5, p. 80) as to the difficulty of identifying the S. rugosa of 

 Bosc to which this form has been referred by Ferussac and D'Orbigny. 



7. Polypus L. Hoyle. Fauna and Geography Lace, and Maid. Archip. (J. S. 

 Gardiner), Vol. ii. Supp. i. 1905. 



One example, sex indeterminate, young, Amirante, 20—40 fathoms (1407). 

 This young example agrees in all respects with the form recorded by Hoyle, except 

 that there are two, not three, ventral chromatophores. 



8. Polypus P. (Plate 65, fig. 3 ; Plate 66, fig. 4.) 



One example, ?, from off" Peros, Diamant Is., 12 fathoms (1410). 



This specimen proved to be too young to be treated as a new species. It exhibits 

 affinities with P. horsti, P. fontanianus and P. gardineri, but at the same time appears 

 to be specifically distinct from these forms. 



The body is posteriorly rounded and sac-like, the eyes are tolerably prominent and 

 between the latter the head is slightly wider than the body. The skin is wrinkled 



