216 Rev. T. Hincks on British Polyzoa. 



Locality. On rocks near low-water mark, and dredged in 

 shallow water off the Capstone, Ilfracombe. 



Distinguished from V. pustuhsa^ its nearest ally, by its 

 smaller size and more delicate habit, by its short and not very 

 dense clusters of cells, which do not extend much below the 

 Joint, while those of the kindred species are elongated and com- 

 pact and occupy a large proportion of the internode, and by 

 the exquisite colour of the tentacles and other portions of the 

 polypide. 



3. Valkeria gracillima, n. sp. 



Stem creeping, rather stout and sinuous : zoooecia disposed 

 in groups of varying size at intervals, slender, elongate- 

 oval when contracted, flask-shaped when the polypide is ex- 

 tended, rounded oif below, of a light horn-colour : polypides 

 with eight tentacles and a powerful gizzard. 



Hob. Creeping over Corallina officinalis. 



This species is not characterized by any very marked feature, 

 but is sufficiently distinct from any form with which I am 

 acquainted. The cells originate on the sides of tlie creeping- 

 stem, but are not as regularly biserial and opposite as in V. 

 caudata ; they are also more delicate, of rather smaller size, 

 and less cylindrical than those of the latter species. The 

 groups of cells are small, usually consisting of about three or 

 four. The gizzard is very conspicuous. 



I am indebted to Mr. Leipner's kindness for the oppor- 

 tunity of describing this species also. 



Genus Aeachnidium*, Hincks. 

 Avaclinidiuni clavatum^ n. sp. 



Zoariiim forming an irregular network : zoooecia clavate, 

 elongate, enlarged above, rounded at the top, and tapering off 

 below ; orifice small, placed near the upper extremity. 



Locality. On the tests of Ascidians, Shetland. 



Distinguished from the only other species, A. hipjjothooides^ 

 by its elongated, fclavate cells, and the absence of the fibrous 

 processes round the margin. The cells are also larger and 

 more definite and constant in shape. The papilla marking 

 the orifiice seems to be smaller and less prominent than in the 

 last-named species. 



A. clavatum spreads over the tests of Ascidians from 

 Shetland, for which I am indebted to Mr. J. G. Jefl^reys. 



* The generic name was published at first as Arachnidia — wrongly, 

 iua; much as !t represents the Greek dpa^vlBiov, dim. of dpdxviov, a spider's 

 web. 



