302 _ GILMAN A. DREW 
EXPLANATION OF FIGURES 
All of the figures that represent the attitudes of squid were drawn from memory 
after repeated observations. While each figure is thus really a composite, and must 
represent impressions received rather than the actual positions of particular in- 
dividuals, much care has been given to the preparation of the figures and it is be- 
lieved that the general attitudes are reasonably wellrepresented. Sexually mature 
squid are usually as much as 15 cm. and may exceed 40 em. in length. 
ABBREVIATIONS 
bmi, inner buccal membrane n, nidamental gland 
bmo, outer buccal membrane na, accessory nidamental gland 
d, depression in which sperm reservoirs 0, oviduct 
are attached r, rectum 
g, gill Ss, sperm reservoirs (ejaculated from sper- 
h, modified (hectocotylized) portion of matophores) 
arm sr, Sperm receptacle 
j, Jaws sro, opening of sperm receptacle 
PLATE 1 
EXPLANATION OF FIGURES 
1 Copulating squid showing the positions taken by the animals when the sperm- 
atophores are inserted into the mantle chamber. The figure shows the animals 
during the period the arm of the male is inserted in the mantle chamber of the fe- 
male. Drawn from memory after many observations. 
2 Copulating squid showing the positions of the animals when the spermato- 
phores are placed so that their reservoirs become attached to the outer buccal 
membrane. The figure shows the male in the act of grasping the spermatophores 
with the tip of his arm as they are ejected through the funnel. Drawn from mem- 
ory after many observations. 
3 Acommon attitude of a sexually excited male. The arms are not kept rigidly 
in a set position, but are frequently spread as shown in the illustration and held 
thus for from a few seconds to a minute or more ata time. The drawing is based 
upon sketches made of active animals. 
4 Photograph of the two ventral arms of a male squid, showing the slight modi- 
fication (h) consisting of enlarged peduncles, reduced sucking dises and a ridge 
between the suckers, toward the tip of the left arm. The wrinkles on the arms are 
due to shrinkage. A bit of the outer buccal membrane shows between the arms. 
The arms from which the photograph was made are 93 cm. long. 
