NICOLEA VENUSTTTLA. 153 



The hooks (Plate CXXVI, figs. 2 b to 2 V") present a single tooth above the main 

 fang, though in some traces of a second appear in lateral view. The base is somewhat 

 small in proportion to the crown and neck, and its lower edge is evenly convex. The 

 process on the anterior edge curves upward so as to make a narrow gulf below the main 

 fang, and the edge beneath it is concave. The posterior or dorsal edge has only a slight 

 indentation before joining the base. A series of striations pass from the crown down the 

 posterior part of the neck. The basal region is deep and comparatively short in contrast 

 with Polymnia nebidosa— another form possessing only a single tooth above the main 

 fang. The inferior outline is convex with a slightly sinuous tendency at each end- 

 The posterior hooks in many (Plate CXXVI, fig. 2 c') show two distinct teeth above the 

 main fang. In an example from Christiana Fjord (Canon Norman) the posterior 

 indentation above the base is deeper, but the hook is otherwise similar to that of the 

 British form. 



Habits. —Those inhabiting the tubes in the tissue of Alcyonidium (E. M. and R. M.), 

 attached to stones at extreme low water, had their tentacles thrust out into the 

 surrounding water. The anterior end with the tentacles protruded from the apertures 

 and thus facilitated extraction. Many had their body-cavities filled with ova (May 20th). 

 De St. Joseph found that it left its tube and swam in a serpentine manner through the 

 water. 



The tubes often occur amongst algae and small mussels, and are formed of secretion 

 and minute grains of sand or fragments of shells, the masses sometimes being further 

 encrusted by sponges. In the deep water forms the tube is composed mainly of fragments 

 of shells, an occasional small stone and fragments of Balani and Ditrypa, cemented by a 

 tough secretion. Occasionally it is placed inside a broken valve of Pecten, and thus one 

 area of the circumference is sufficiently protected. Mr. Arnold Watson found one from 

 Llanfairfechan in April wove a cobweb, and he suggests this may be the Terebella textrix 

 of Dalyell. 



Reproduction. — A small female from the East Rocks, St. Andrews, with only one or 

 two divisions of the single pair of branchiae, had numerous ova (Plate CXXIX, fig. 9) in 

 the coelom on June 21st. De St. Joseph gives their colour as orange. There are three 

 pairs of segmental organs, the first in the third segment, the second at the sixth, and the 

 third at the seventh (De St. Joseph). In the males as figured and described by Malmgren 

 in Nicolea arctica (Nicolea zostericola, (Ersted, according to Levinsen, Wiren and 

 Marenzeller) there is a small cirrus above the third and fourth setigerous segments, but 

 such is only the papilla of the segmental organs, which is better developed in the male 

 than in the female. 



The species of the genus Nicolea have long been a source of dubiety to zoologists, 

 and remained so up to date. This was due as much to variation as to misapprehension, 

 for branchiae as well as bristles and hooks varied, and young forms differed considerably 

 from the adult. Indeed its representatives were placed under different genera such as 

 Axionice and Scione, and much confusion has resulted. Marenzeller showed that Scione 

 and Axionice fell under the same genus, and that Nicolea parvula, N zostericola and 

 N. vestita were synonyms of the original Nicolea venitstula of Montagu. It is doubtful if 

 even Nicolea lobata, Malmgren ? and Nicolea flexuosa, Malmgren, are not in need 



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