MOLLUSCA OF PLYMOUTH. 427 



eight additional specimens of Lomanotus. They were all small in 

 size ; the. majority were y\ inch long^ while the smallest was only 

 |- inch and the largest was ^ inch — just the size of Alder and 

 Hancock's Lomanotus flavidus. They were fixed on the stem and 

 branches of a colony of Anteymularia anteunina dredged in seven 

 fathoms water between the Breakwater lighthouse and the Queen's 

 Grounds buoy : their elongate and low form and pale orange coloura- 

 tion — exactly that of the Hydroid — rendered them so inconspicuous 

 that similar specimens have probably been more than once passed 

 over.^ 



Bergh/ in his recent revision of the Cladohejjatica, remarks upon 

 the absence of any knowledge of the bionomics of this genus ; but 

 it should be noticed that the occurrence of so many as eight young 

 individuals upon a single hydroid colony points very strongly towards 

 the conclusion that Lomanotus attaches its spawn upon or very near 

 to the stems of zoophytes, and that the veliger-stage in the develop- 

 ment is passed through in the egg, or that the free-swimming stage 

 is of very short duration, for otherwise the larvse would be dispersed 

 over a wide area, and the chances would be greatly against the con- 

 gregation of the young metamorphosed individuals upon a single 

 hydroid stock. I have already shown that Lomanotus possesses a 

 power of rapid motion through the water (1. c, p. 189), so that even 

 if a free-swimming larval stage is absent in this genus the dispersal 

 of the species can be readily effected by the movements of the adult. 



The structure of these young specimens is shown very fairly by 

 figs. 1 and 2 of PL XXVIIl, representing two different individuals 

 of the same size {-^^ inch long), one seen from the side, the other from 

 above. The form in a healthy and active individual is elongate and 

 slender, being broadest just behind the rhinophores, and tapering 

 gradually to the posterior extremity, l^ig. 2 was drawn from a very 

 active specimen, while alive, and shows the characteristic shape. 

 Colour, a pale transparent orange, exactly that of the majority of 

 healthy colonies of Antennularla. In some of the specimens the 

 colour was enriched by red-brown spots on the tubercles of the 

 rhinophoral sheaths and on the papillae of the lateral (pleuropodial) 

 folds. This red-brown pigmentation was quite absent in the smallest 

 individual (| inch), but in the two largest was considerably developed, 

 and gave the animal a more conspicuous appearance (not on the 

 Hydroid, however, for the small oval sporosacs situated all down the 

 stem have also a deeper colouration than the stem itself, and the 



' I have indeed since found two other specimens in the preserved collection of Antennu- 

 laria ratnosa. 



^ Loc. cit., p. 50 : " Die Lomanoten scheinen ziemlich trage Thiere zu sein, iiber deren 

 biologische Verhaltnisse nichts bekannt ist." 



NEW SERIES. — VOL. I, NO. IV. o2 



