pecleiiney 
X. Descriptions of some new and rare Cephalopoda, (Part 11.) 
By Professor Ownn, C.B., F.RS., F.Z.S., &e. 
Received 2nd March, read 20th April, 1880. 
[Prates XXTII.—XXXV.] 
SINCE the publication of the paper “On some new or rare Cephalopoda,” in the 
second volume of the ‘Transactions of the Zoological Society’ (1842, p. 103)1, I have 
not omitted any opportunity of acquiring and promoting the acquisition of specimens of 
that class, and now submit to the Society a selection of such materials as seem worthy 
of forming a second contribution on the subject. 
Class CEPHALOPODA, Cuvier ?. 
Order DIBRANCHIATA, Owen ?. 
Suborder Octoropa, Leach 4. 
Genus TRITAXEOPUS, Owen ®. 
Species TRITAXEOPUS CoRNUTUS, Owen. (Plate XXIII.) 
The ‘ Poulpes,’ or eight-armed Cephalopods, as a rule, bear their suckers in two rows 
along each arm. But, however numerous and seemingly “ opposite” in arrangement, 
they are “alternate;” and this order becomes more obvious as the suckers are fewer 
in number and further apart on the acetabuliferous surface. There are also species in 
which the zigzag course becomes so opened out that the suckers appear to be in asingle 
series, at first along the distal half of the arm, as in Octopus lechenaultii; and finally, 
with a feeble indication of the zigzag at the basal part, the suckers curve in a linear 
course to the end of the arm, giving the character on which the generic group E/edone * 
is founded. 
Other genera or subgenera of the Octopoda have been based on marginal extensions 
of the arm-membranes (Cistopus, Pinnoctopus, &c.); but I have hitherto failed to find 
a notice of any Octopod characterized by having the brachial acetabula in three recog- 
nizable series along more or less of each arm. 
This, however, is the constant character of an Australian species in other respects 
1 Communicated February 23rd, 1836. See * Proceedings’ for that year. 
2  (éphalopodes,” Tableau élémentaire de Histoire Naturelle des Animaux, 8yo, an 6 (1797 ), p- 378, 
3 Memoir on the Pearly Nautilus, 4to, 1832, p. 56. 
4 Zoological Miscellany, iii. (1817); “ Fribus Octopoda,” Trans. Zool. Soc. ii. (1841), p. 129. 
® éredwvn, Arist.; Eledone, Cuy.; Eledon, Leach, 
Z 
° zpeis, three; rags, rank; ous, foot. 
VOL. XI.—pPart v. No. 1.—June, 1881, 
