(Continued from page 422) 
the inner tunic and the outer membrane, but I am not certain this is the ex- 
planation. X 20 diameters. 
18 Transverse section of a spermatophore through the region of the spiral 
filament. For position see figure 1. X 70 diameters. 
19 Transverse section of a spermatophore through the region of the oral end 
of the cement body. For position see figure 1. X 70 diameters. 
20 Transverse section of a spermatophore through the region of the aboral 
end of the cement body. For position see figure 1. X 70 diameters. 
21 Transverse section of a spermatophore through the region of the sperm 
mass. For position see figure 1. % 70 diameters. 
22 Transverse section through the case of an ejaculated spermatophore. For 
position see figure 16. % diameters. 
PLATE 3 
EXPLANATION OF FIGURES 
23 and 23A Two continuous portions of the oral end of the same spermat- 
ophore dissected from a spermatophoric organ. The oral end of 23 was near the 
point (’, figure 32. The cement body was just beyond the point C?. The aboral 
end of the spermatophore (not represented in the figure) was near the distal end 
of the middle tunic gland. As the middle tunic is evidently almost completely 
formed, it would probably soon have been passed on to the outer tunic gland. 
x 70 diameters. 
24 Oral end of a forming spermatophore dissected from a spermatophoric 
organ. The oral end had passed through that portion of the outer tunic gland 
that connects with the middle tunic gland, and had passed into the finishing gland 
duct. Theextreme end was near the point where this duct widens into the finishing 
gland. The aboral end of the specimen (not shown in the figure) was well back 
in the hardening gland and the cement body region was in that part of the outer 
tunic gland that extends up into the hardening gland. The outer tunic was elastic 
and would not adhere to a needle on that portion in the hardening gland, and was 
soft and sticky over the whole oral extremity. This portion had ‘not been in 
the hardening gland and would not have entered it. X 70 diameters. 
25 Oral end of a forming spermatophore dissected from a spermatophoric 
organ. The oral extremity had reached the pointed end of the finishing gland and 
the aboral end (not shown in the figure) was in the finishing gland duct. The 
whole of the outer tunic, oral as well as aboral end, was elastic and would not 
adhere to a needle, but the spermatophore was not yet as turgid nor as small as 
those more fully formed. The shrinking of the oral end, the formation of the 
cap and the accompanying changes in the ejaculatory apparatus are the chief 
features to be understood. X 70 diameters. 
26 Oral end of a forming spermatophore dissected from a spermatophoric 
organ. It was contained entirely within the finishing gland and had its ex- 
treme oral end very near the opening of the spermatophoricduct. X70diameters. 
27 Oral end of a forming spermatophore dissected from a spermatophoric 
organ. The oral end had entered the spermatophoric duct. 70 diameters. 
28 Oral end of a spermatophore dissected from a spermatophoric duct. A 
slight shrinkage, especially at the oral end, is the only change to take place in 
completing the spermatophore. X 70 diameters. 
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