LA.R SABELLARUM. 425 



a well-known family of l)ir(ls. It is difficult to form aiiotlicr in accordance witli the principles 

 which have rcgidated the nomenclature of the present monograph. The nearest approach to 

 uniformity will, perhaps, be attained by the use of the name Hydrolarid*, which I have 

 accordingly adopted. 



LAR, Gosse. 



Name- — Yxoxa Lar, a household god, in allusion to the mode in which the only known 

 species is associated with Sabella. 



TROPHOSOME. — Htdroehiza a creeping filiform stolon covered with a peeisarc. 

 Hydranths fusiform ; hypostome separated by a constriction from the body ; oral 

 lobes in the form of two opposable plates. 



GONOSOME. — Planoblasts borne on blastosttles which spring from the 

 hydrorhiza and terminate distally in a globular cluster of thread-cells. Medusa at 

 time of liberation with a sub-globular umbrella; manubrium moderately large, 

 destitute of oral tentacles ; marginal tentacles six, with bulbous bases destitute of 

 ocelli. 



The trophosome of this remarkable genus was described some years ago l)y Mr. Gosse. 

 Nothing, however, of its gonosome was known until Mr. Ilincks had the good fortune to obtain 

 it on the northern coast of Devonshire. To him, therefore, we are indebted for rendering us 

 acquainted with the missing element, which was needed for a complete diagnosis of the genus, 

 and which can alone remove it from the domain of provisional genera, to which it would 

 otherwise have to be relegated. 



Lab, SABELLARUM, Gosse. 



Lar SABELLARUM (trophosoiiie), — Gosse, in Trans. Linn. Soc, vol. xsii, 1857, p. 113, pi. xx. 



(Trophosome and gonosome), Hincks, in litteris, 

 July 5th, 1872. 



TROPHOSOME. — Htdraxtos attaining a height of about Toth of an inch, 

 scattered at short intervals on the creeping hydrorhiza ; hypostome witli a patch of 



