THE ORGAN OF VERRILL IN LOLIGO. 
97 
The Organ of Verrill in Loligo. 
By 
Malcolm Laurie, B.Sc. 
From the Zoological Laboratory of University College, London. 
With Plate XL 
In a paper on North American Cephalopoda 1 Verrill describes 
a valve-like organ at the base of the siphon in Desmoteuthis 
and Taonia, in both of which genera the true valve is absent. 
His drawing of this structure in Desmoteuthis tenera is re- 
produced in fig. 1. It is there seen to be composed of a median 
portion, ( m .) lying on the dorsal side of the siphon, and a pair 
of lateral cushions (n. n ' .). The median portion is raised into 
three papillae, one (i.) median and a pair ( i '.) more posterior in 
position. 
This structure to which the name of Verrill’s organ has 
been given by Hoyle 2 has been observed in a few other species, 
but is by no means common. It is figured by Mr. Weiss in 
the present number of this Journal for several Oigopsidae (see 
PI. VIII, fig. 2 ; PI. IX, fig. 8 ; PI. X, fig. 10). I was there- 
fore much interested to discover, in sections of a young 
Loligo about G mm. in length, made in Professor Lankester’s 
laboratory at University College, London, a structure in the 
siphon which I think there is no doubt is Verrill’s organ. 
The general appearance of this structure is shown in fig. 2. 
It consists of a median dorsal cushion, which is prolonged 
1 ‘ Trans. Conn. Acad.,’ vol. v, part 2. 
2 ‘ Challenger Report,’ vol. xvi. 
VOL. XXIX, PART 1. NEW SER. 
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