ON CEPHALOPODA FROM THE MONTE BELLO ISLANDS. 677 
38. Cephalopoda from the Monte Bello Islands. 
By G. C. Rozson, B.A.* 
[Received March 18, 1914: Read June 9, 1914. | 
(Text-figure 1.) 
INDEX. 
Structure : Page 
Radula, mandibles, poe ee of Sepiadariwm 
CUFURHT Oy SDo1s- sonaccocooc9 sosonayocconscoodeacceannne LOE (ots) 
Variation, &c.: 
Differences between Peay eee and Sa ees 
stunmarized . paene ee 677 
eeuie sar imm natnibuam, sp. n., Gntern me vediate betwe een 
epiadarium and Sepioloided .............20000-..... 877 
Geographical Zoology : 
Distribution of Sepiadariwn auritum, probably 
DUO MALO USA eae ee ee ee Ons 
Systematic : 
SCPC PONTO. GOUFUCRUID, SOs Ne cosooenceacdonscosespouane Whe’ 
Of the two species of Cephalopoda obtained by Mr. P. D. 
Montague from the Monte Bello Islands, one specimen is of 
considerable interest—-a Myopsid which has been referred after 
some hesitation to Sepiadarium. 
The differences between the latter genus and the closely-allied 
Sepioloidea, though they have been touched upon by several 
authors, have not been fully summarized as yet. The following 
table gives the more important differences :— 
Sepradarium Steenstrup. Sepioloidea d’Orb. 
1. Funnel attached to mantle by a .... by cartilaginous plugs of the 
ligament (1) (2). mantle that fit into sockets on 
the funnel (1) (2). 
2. Ventral pores absent (2). .... present (2). 
3. Mantle fringe absent (2). .... present (2). 
4. Fins short (4). 65 0 komme (2); 
5. The hectocotylized arm bearing Suckers of the hectocotylus per- 
on its distal half a series of sisting as small papille ; the arm 
transverse ridges, which are the grooved diagonally on its inner 
laterally produced peduncles of side (4). 
the suckers (4). 
In respect of Nos. 1, 2, 3, and 5 in the above list, the form 
here described is referable to Sepiadarium. The length of the 
fins, on the other hand, suggests aftinity with Sepioloidea. It is 
not desirable on such slender grounds, however, to create a new 
genus intermediate between the two forms under discussion for 
the reception of this species. But it is certain that in the 
present state of our knowledge we are entitled to regard this as 
an unusual form of Sepiadariwm, intermediate in respect of one 
character between that genus and Sepoloidea. 
* Communicated by Prof. J. Sranzey Garprner, M.A., F.RS., F.Z.8., and 
published by permission of the Trustees of the British Museum. 
