. Bulletin of the Museum of Comparative Zoology at Harvard College. Zoology. 12 Bulletin Museum of Comparative Zoology, Vol. 150, No. 1. mm Figure 8. Unnamed species of Spinula. Internal view of left valve of a specimen from Station 83 to show details of hinge plates and shell outline. tor muscle is more rounded, the larger 'quick' and smaller 'catch' parts being clearly visible. The siphonal tentacle originates on the right side and is insert- ed close to the base of the siphon. The foot, while large, is not as large as it is in the other species described here. However, the 'byssal' gland is
. Bulletin of the Museum of Comparative Zoology at Harvard College. Zoology. 12 Bulletin Museum of Comparative Zoology, Vol. 150, No. 1. mm Figure 8. Unnamed species of Spinula. Internal view of left valve of a specimen from Station 83 to show details of hinge plates and shell outline. tor muscle is more rounded, the larger 'quick' and smaller 'catch' parts being clearly visible. The siphonal tentacle originates on the right side and is insert- ed close to the base of the siphon. The foot, while large, is not as large as it is in the other species described here. However, the 'byssal' gland is extremely large and spherical in form. The gills are carried high in the mantle cavity parallel to the postero-dorsal shell margin. Thirteen gill plates are present on each demibranch in the present spec- imen. The mouth is set just posterior to the anterior adductor, the palps extend- ing little more than half way across the body. In this specimen there are 30 fine ridges; the anterior part of the right palps is overlain by the coils of the hind gut. The contracted palp proboscides are no- ticeably short and stubby. The stomach and style sac are relative- ly small, barely extending into the ven- tral half of the foot. Similarly, the hind gut does not extend deep into the foot, as is the case in Spiinila filatova. Like the latter species, the first section of the hind gut lies close to the posterior body wall and extends just ventral to the pedal gan- glion, where it turns dorsally taking one V-turn behind the stomach before pass- ing to the right side of the body at a point close to the posterior dorsal margin of the shell. It forms seven visible coils on the right hand side of the body which are stacked one above the other; each coil is offset in an anterior direction adjacent to the anterior inner hinge margin. The pedal ganglion is large, positioned in the posterior part of the neck of the foot. The visceral ganglion is cylindrical, terminating close to the posterior adduc
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Keywords: ., bookauthorharvarduniversity, bookcentury1900, booksubjectzoology
