POLYCILETA. 305 



sand-grains was present in the same bottle with Eupomatus heteroceros, Eunice 

 antennata, etc. ; no locality being given : probably South-east Cheval Paar. 



In the second of the above-quoted publications Grube makes the important 

 correction that the uncini are not 4-dentate, as previously stated, but 5-dentate. This 

 species resembles L. medusa in the number of scuta ventralia, and consequently in 

 the occurrence of five pairs of tori behind the scuta. These posterior tori touch one 

 another in the middle line in their respective segments. 



The specimen in the preserved state has a nearly uniform pale flesh tint, only the 

 branchiae, which are matted together, showing up dark. There is no great contrast 

 between the diameter of the thorax and that of the abdomen ; the latter is sub- 

 cylindrical, smooth, somewhat varicose. The total length is about 80 millims,, and 

 the number of segments about 60, the maximum width 7 millims., thus presenting a 

 close numerical correspondence with Grttbe's original type. The scuta ventralia are 

 narrow as in the angustescutate variety of L. medusa. This species is said by Grube 

 to differ in colour from L. medusa, but in the preserved state the chief characteristics 

 are the nearly even diameter of the body, the uncini of the biserial tori and abdominal 

 pinnules which are 5-dentate, to which may be added the pale flesh colour. The fifth 

 denticulation at the vertex of the uncinus is small but distinct. The average width 

 of the thorax (excluding the capillary fascicles) may be estimated at 6 millims., that 

 of the abdomen at about 5 millims. At the same time, if it were not for the 

 quinquedentate uncini, I should probably have placed the worm under L. medusa. 



In the living condition more fundamental differences may come to light. The worm 

 was closely invested by its tube. The preserved specimens of L. medusa have a dark 

 neutral colour in marked contrast with the pale flesh colour of this worm. A second 

 smaller specimen shows very clearly the quinquedentate uncini of the abdominal 

 pinnules. In this case the abdominal region is more attenuated, and the scuta ventralia 

 end rather sooner, so that there are six pairs of tori behind them. 



Grymaea, Malmgren, 1865. 



Three pairs of acervi of filiform branchiae. 



( !apillary fascicles commencing from the second segment (first branchiferous segment) 

 and extending to the posterior abdominal region. 



Tori uncinigeri commencing on the fourth (? or fifth) setigerous segment. Uncini 

 avicular, uniserial. 



Malmgren says the tori commence on the fifth setigerous segment, but in a 

 specimen of the type species, Grymcea bairdi, Malmgeen, collected off Norway by the 

 Rev. Canon Norman, which I had the opportunity of examining at the British 

 Museum some years ago, they commenced on the fourth setigerous segment. 



Grymsea cespitosa, n. sp. Plate VII., figs. 164 and 165. 

 One specimen, incomplete behind, was obtained, in 40 fathoms, south of Rameswaram 

 Island, at Station LIV. 



2 R 



