356 THE PLANKTON OF THE FAROE CHANNEL AND SHETLANDS. 



large cinnamon-coloured oil drops are irregularly distributed in its 

 contents. 



Diameter of calymma, 2-6 mm.; of central capsule, 14 mm.; of the 

 nucleus, -18 mm. 



CCELODENDEIDA. 



CcELODENDRUM RAMOSISSIMUM is not unfrequently found in Shetland 

 waters, and I have captured it on the east as well as on the north and 

 west sides. 



The skeletal tubes branch dichotomously, each sub-branch doing the 

 same, and becoming progressively smaller and thinner towards the 

 periphery. These tubes are hollow, and the branches are given off 

 nearly at right angles. The smallest and terminal twigs are each sur- 

 mounted by eiglit small recurved teeth and end in a knob. The main 

 branches arising from the galea are closed. At each pole three branches 

 arise from the galea, two being together and one a single one. The 

 central capsule is enclosed in a two-valved shell, with numerous large 

 pores of irregular size, a peculiar hard ridge on the surface, and a 

 curved process at the side, Tlie shell is perforated at the base and 

 sides by small, round, irregular pores. 



The phreodium is large. Diameter of the entire animal, '8 mm. ; 

 length of principal branches, "07 mm. ; diameter of shell valves, 

 '06 mm. 



AULOCANTHIDA. 



AULACANTHA SCOLYMANTHA {Hcieckel). Plate I., Fig. 3. 



This is a common Eadiolarian round all the coasts of Shetland, where 

 I have taken it in greater abundance than in the open waters of the 

 Faroe Channel, As the spines are almost invariably toothed, whereas 

 in Haeckel's A. Iccvissima (the only known habitat of which is the 

 Faroe Channel) the spines are smooth, my species cannot be referred 

 to the latter. At the same time it must be remarked that they do 

 not quite agree with A. scolymantha as received (in the preserved con- 

 dition *) from Naples, nor quite with Haeckel's pictures (Monograph, 

 1862), the differences being in the almost invariably excentric position 

 of the central capsule, the smaller quantity of phicodium, and the 

 character of the radial tubes. These taper at each end, and are 

 thickest in the middle, Tlie proxinal end tapers to a rounded 

 extremity, and the distal to a blunt point. Many tubes are slightly 



* In my exi)eiieuce no methcid of preservation retains the form of the animal in such 

 a normal condition as the well-known 5 per cent, formalin. Specimens may be observed in 

 detail on shore when opportunities fail — as they usually do — at sea, within a few weeks 

 with practical certainty that the organisms have retained their normal condition. Spirit 

 or other preservative certainly distorts to a considerable extent. 



