310 POLLICIPES POLYMEPvUS. 



two cement- ducts, after running down the sides of the 

 peduncle in a sinuous course, within the longitudinal 

 muscles and close outside the ovarian tubes, pass through 

 the corium, and then separately form the most abrupt 

 loops or folds. These are represented in PL IX, fig. 2, 

 in which a space about T Vth of an inch square is given, 

 as seen from the outside. At each of the bends, an 

 aperture has been formed through the membrane of the 

 peduncle, and cement poured forth. The manner in 

 which the discs of cement (b) come out of the two ducts 

 (a a), and reach the external surface, is shown in the 

 section, figure 2 d . The two tubes are firmly attached to 

 the older layers of membrane, and are covered by the last- 

 formed layers. In a young specimen, the cement-ducts 

 were a little above ^ths of an inch in diameter, which 

 had increased, in a medium-sized specimen, to ^. The 

 cement-glands are retort-shaped, seated near each other, 

 high up in the peduncle. 



Size. — The largest specimen which I have seen, was 

 three inches in length including the peduncle ; the capi- 

 tulum was T%ths of an inch long, and one in width. 



Young Specimen. — 1 examined one with a capitulum 

 Troths of an inch long, measured from the lowest whorl 

 to the tips of the terga ; the width was only Tilths of 

 an inch ; in old specimens the width of the capitulum is 

 greater than the length. The length of one of the scuta 

 was tAo oths of an inch, therefore, greater than the width 

 of the entire capitulum, which is not the case with mature 

 specimens. Besides the scuta and terga, the carina and 

 rostrum, and three pair of large latera, there was a lower 

 whorl formed of ten or twelve valves, giving altogether to 

 the capitulum of this very small specimen, either twenty- 

 two or twenty-four valves. 



Shape of Body, Sack, Colours, <^e.-^From the posi- 

 tion of the orifice of the capitulum, the animal's body is 

 suspended to the scuta in a more transverse direction 

 than is usual. The prosoma is well-developed, and is 

 distinctly separated from the three posterior thoracic seg- 



