116 Ilev. T. Hincks on Prof. Heller's Catalogue 



apex of the distal nectocalyx ; and liaving run along the 

 poljpe-groove as far as the fundus of the nectosac, where it 

 was surrounded by a tubular process of endoderm, it also ter- 

 minated in a bifurcation, the resulting branches being distri- 

 buted to the upper wall of the sac, as in the former case. 



Though the movements of Diphyes are very variable, the 

 normal position is that in which the chaplet of polypes trails 

 from the groove of the distal nectocalyx, the nectosac being- 

 superior or on the neural side. 



The nectosacs give propulsion to the whole organism, with 

 the pointed extremity of the proximal nectocalyx foremost ; 

 nevertheless I am disposed to think that the movement is 

 truly retrograde, as in the case of the cuttlefishes ; and if this 

 be true, all the terms of relation used in the description of 

 animals having a bilateral symmetry will be applicable to 

 Dijihyes. 



H.M.S. 'Lord Warden.' 

 Gibraltar, Oct. 10, 1871. 



XV. — Note on Prof. Heller's Catalogue of the Hydroida of 

 the Adriatic'^. By the Eev. Thomas Hincks, B.A. 



We are indebted to Prof. Heller for very valuable contri- 

 butions to our knowledge of the Invertebrate fauna of the 

 Adriatic. In 1867 he published at Vienna an admirable 

 Catalogue of the Polyzoa which occur in that sea, containing 

 descriptions and figures of a large number of new s})ecies. In 

 1868 he continued his work, and dealt with the Zoophytes 

 and Echinodermata of the same region, in the paper which is 

 the subject of the present communication. The zoology of 

 the Adriatic has been illustrated by a long line of able inves- 

 tigators, extending from the times of Donati and Olivi (1750- 

 1792) to the present day ; but Prof. Heller has shown us that 

 its riches were far from being exhausted. It is unnecessary 

 to say a word as to the value of such local catalogues and the 

 relation which they bear to the interesting problems connected 

 with geographical distribution. It is obvious, however, that, 

 inasmuch as they form the storehouses from which the theorist 

 draws his facts, it is of the first importance that they should be 

 characterized by rigorous accuracy in the discrimination and 

 identification of species. In that portion of his work which 

 relates to the Hydi-oida, Prof. Heller has needlessly increased 

 the chances of error, has rendered, indeed, a certain amount of 



* " Die Zoophyten uiid Ecliinodermen des Adriatischen Meeres, von 

 Prof. Cam. Heller in Innsbruck," 18G8. 



