THE PENNATUUDA DREDGED BY H.M.S. "PORCUPINE." 455 



Description of Species. 



Order PENNATULIDA. 



Section I. Pennatule^e. 



Subsection i. Penniformss. 



Family 1. Pteroididse. 



Genus Pteroides (Herkl.). 



Pteroides griseum (Koll.). 



Of this form eight specimens were obtained from Tangier Bay, all imperfect, 

 and evidently broken by the dredge : of these, six have been broken off sharp 

 at the middle or lower part of the rachis, one consists of the rachis entire with 

 about an inch of the calcareous axis of the stalk, and one of the entire stalk 

 with only the lower part of the rachis still attached. 



Out of this species Kolliker has erected two varieties, brevispinosum and 

 longispinosum, both of which are represented among our specimens ; but no 

 sharp line can be drawn between them, the one variety passing into the other 

 by slight gradations. Our specimens present no feature worthy of remark, 

 beyond the fact that the feather is in all cases slightly longer than wide; 

 whereas Carus gives as a part of the definition, " latior quam longior. " The 

 longest specimen reaches only to 7*5 cm. 



One specimen, consisting of the rachis only, does not agree exactly with any 

 of Kolliker's descriptions. The softness of the rachis, the greater distance 

 between the pairs of leaves, and the shape of the leaves, resembling more a 

 sickle than a fan, give it a very different appearance to that of the more ordi- 

 nary form ; but P. griseum is so variable that we have hesitated to found a new 

 species for the reception of this specimen. The dimensions are as follows : — 

 Length of rachis (incomplete), 3*6 cm.; length of leaf, 1*5 cm.; breadth of 

 feather, 2 - 8 cm.; breadth of leaf, 6 mm. ; number of pairs of leaves, 15; number 

 of rays (Hauptstrahlen), 7 ; distance of leaves apart, *5 cm. The rays are pro- 

 minent up to the top of the rachis ; the siphonozooid plate short and broad. 



Kolliker (3), pp. 66-71, pi. iii. figs. 21-23 ; Carus (4), p. 63. 



Family 2. Pennatulidse. 

 Genus Pennatula (L.). 

 Pennatula phosphor ea (L.), var. aculeata (Koll.). 



Two specimens of this variety were dredged at Station 6, 1870, in length 

 12*8 cm. and 9*5 cm. The first, which is entire, bears 7-9 autozooids on each 



