INVERTEBRATA, CRYPTOGAMIA, MICROSCOPY, ETC. 883 



bauds and of the eye-spots is to be correlated with their parasitic mode 

 of life. 



Pelagic Annelids from the Canary Islands.* — Prof. Richard Greeff 

 describes several interesting species found by him off the coast of 

 Lanzarote, one of the Canary Islands. 



1. Acicularia Virchoicii. — This animal attains a length of 5 to 

 9 mm., its greatly elongated body consisting of twenty-six to thirty- 

 nine segments. The head-segment or prostomium is prolonged into 

 a movable conical frontal process, which serves as a tactile organ. 

 The head also bears a pair of leaf-like parapodia, directed somev/hat 

 forwards. These properly belong to the second segment or peristo- 

 mium, but there is no separation between the two. The remaining 

 segments bear outwardly dii-ected parapodia, each consisting of 

 notopodium and neuropodium, with a small prominence between them 

 bearing sette. The form of the two divisions of the parapodium is 

 curious : each is more or less quadrate in outline, and attached, 

 mushroom-like, by a stalk on the centre of its inner surface. 



On the surface of the parapodia are a number of circular disks, 

 each made up of numerous facet-like areas, like a compound eye. 

 Further examination of these bodies shows that each consists of a 

 dee]) cup-like depression of the surface, filled with a bundle of close- 

 set parallel rods, some of which are occasionally seen projecting far 

 beyond the surface of the disk, having evidently been partially ejected. 

 Observation of the living animal showed that these curious organs 

 acted as adhesive disks ; they adhered to the slide and cover-slip, 

 sometimes the whole follicle being extruded and looking like a stalked 

 sucker. It seems probable that they may also act as urticating organs. 



A description is also given of the alimentary canal, nervous system, 

 and generative organs : a dorsal vessel containing a clear colourless 

 fluid was made out. 



The author found a larva of Acicularia, on the point of metamor- 

 phosing ; it was chiefly distinguished from the adult by its circlet of 

 long, outstanding setfe just behind the head. 



2. Pontodora pelagica (nov. gen. et sp.). — The most interesting point 

 about this species is the character of its segmental organs, which 

 open by ciliated apertures at the summits of little stalked, cup-like 

 structures on, and at the base of, the parapodia. Sometimes each cup 

 has several ciliated apertures, sometimes only one, in which case it 

 bears a strong resemblance to a Vorticella. The internal apertures of 

 the segmental organs were not observed. The length of the body is 

 1 • 6 mm. 



Greeff places Ponfodora in the family Syllidce. 



3. Pelagohia longicirrata (nov. gen. et sp.). — In this species, which 

 attains a length of 3 mm., there was no prostomiiim to be seen, the 

 mouth being, to all appearance, actually terminal. There are no true 

 peristomial cirri, but the peristomiimi bears, on each side, a pair of 

 short simple feeler-like processes, and, farther back, a ciliated lobe. 

 A pair of simple eyes, with lens and pigment, is present in this 



* ' Zeitschr. wise. Zool.,' xxxil. (1879) p. 237. 



3 N 2 



