NOTES ON JASSA FALCATA (Mont.). it 
seen IIm? moult into a large adult form, so that 
Nebeski is clearly mistaken. But the penultimate stage 
varies considerably; in a gathering from Port Erin 
breakwater (not more than 300 yards from the buoy), 
taken November, 1892, there is no projecting tooth in 
the middle of the palm: the adult males are smaller 
(5 mm. to 7 mm., 2nd gnathopods 1:3 to 2 mm. long), 
and have a shorter and more pointed ‘‘ thumb ’’—in 
fact, they nearly resemble Nebeski’s Im?, m*, which are 
probably adult males of the ‘‘ breakwater’’ form. In 
both stages the males have the lower antenne thickly 
clothed with plumose setae, of which the ‘“‘ buoy’’ 
Specimens are destitute. There are 12 males in the 
penultimate and 14 in the adult stage in the “‘ break- 
bd 
water’”’ collection: there are no intermediate forms. 
Belonging to this or, more probably, to the final 
stage, is the form described by Professor G. O. Sars as 
Podocerus odontonyx (Amphipoda of Norway, p. 597, 
Pl. 213, f. 2), and previously by me as P. herdmani 
(Trans. Liverpool Biol. Soc., Vol VII (18938), p. 79, 
f. 13). I have more than once published my opinion that 
this is probably only a form of /. falcata,* and the 
occurrence of two specimens in this gathering confirms 
it. There are also two specimens in the above-mentioned 
‘‘preakwater’’ collection, two in a_ gathering of 
J. falcata from the bottom of the ‘‘ Clio’’ in the Menai 
Straits, and three in one from Puffin Island. It is 
always a small form, measuring in this instance 6 mm. 
The specimen originally described as P. herdmani, 
taken by Professor Herdman from a Compound 
Ascidian off the Island of Bute, measured only 3 mm., 
and was accompanied by two ovigerous females respec- 
tively 3 mm. and 4 mm. long. It may here be mentioned 
* See Ann. and Mag. Nat. Hist., Series 8, Vol. VI, 1910, p. 33. 
