Zoological Society. 3Q I . 



A single bilobed organ, of a bright orange or red colour, similarly- 

 connected with the anterior extremities of the nidamental glands, 

 exists (as was long since pointed out by Swammerdam) in the Cut- 

 tle-fish. In Sepiola the corresponding body is single, and of a rose 

 colour. And there exist two such bodies in a small Cephalopod 

 taken by Caj)t. Ross on the shore of Boothia, which Mr. Owen has 

 recently described under the name of Rossia palpehrosa. Consider- 

 ing the bright colours which these bodies commonly present, and 

 their structure and relations to the generative apparatus, Mr. Owen 

 feels authorized in regarding them as analogous to the suprarenal 

 bodies, hitherto regarded as peculiar to the Vertebrate series. 



The small Octopus described by Mr. Owen was obtained by Mr. 

 George Bennett, like the Loligo laticeps, among the Sargasso weed; 

 which forms, as it were, a bank in the midst of the ocean, affording 

 shelter to many marine animals of littoral genera. The condition 

 of the generative organs would appear to indicate that the specimens 

 brought home were not adult, and the species consequently may be 

 assumed to attain a greater size than that of the largest individual 

 in the collection, which measures only 1-i- inch from the end of the 

 sac to the extremity of the longest arm. Of the eight arms the first, 

 or dorsal, pair is the longest, as is the case in many species of Oc- 

 topus ; the second pair is nearly of the same length as the first ; the 

 third pair (which in the Decapods is commonly the longest) is scarcely 

 half the length of the first ; the fourth pair is nearly two thirds of 

 the length of the first. The musculo-membranous web, which is 

 usually extended betM'een the bases of all the arms in the Octopi, is 

 in this species developed to the ordinary extent between the four 

 dorsal arms only : the webs between the second and third arms, 

 and the third and fourth arms, on each side, are very short ; that 

 between the fourth pair is wanting. From this peculiarity Mr. Owen 

 proposes to name the species Octopus semipalmatus . 



Its anatomy generally agrees with that of Oct. vulgaris. 

 The remaining specimens described by Mr. Owen are the shell 

 and animal of Argonauta hians. Lam. They were obtained in lat. 

 4° S.,|long. 17° W. The animal was alive at the time of its capture 

 by Mr. George Bennett, but fell out of its shell when it was moved 

 on the following morning. A mass of eggs was then exposed in the 

 involuted portion of the shell, which increased so greatly in size after 

 being put into spirit that they now occupy so much of the cavity 

 that not more than one third of the body of the parent could be 

 forced into it. 



Referring to the fact that the Cephalopods hitherto found in the 

 shells of each species of Argonauta have invariably presented 

 characters as specifically distinct as those of the shells in which they 

 were found, each species of animal having appropriated to it its own 

 peculiar species of shell — a fact which extends not only to Arg. 

 Argo, Arg. tuberculata, and Arg. hians, but also to an undescribed 

 species obtained in the Indian seas by Capt. P. P. King, R.N., for 

 which Mr. Owen proposes the name of Arg. rufa, he is disposed to 

 believe that the shell really belongs to the animal that occurs in it. 



