THE C0LLECTT0I5' OE MISS H. GATTT. 153 



long cylindrical corbula. This possesses about twenty costae, 

 each of which carries about seven denticles and has a short blunt 

 spur at its base. Indications of an intracostal septum may be 

 seen in a broad line which extends in each costa from a point 

 near its base to within a short distance of its summit. The 

 peduncle of the corbula carries two hydrothecae. Another striking 

 feature consists in the peculiar denticulation of the hydrotheca- 

 margin, with its broad furcate tooth on each side in front, and 

 long pointed tooth behind. The hydrocladial internodes are 

 short, and the hydrothecae in consequence closely approximated. 



Halicoekaeia. 



Halicoeis^aeia miteata, n. sp. (PI. XXII. figs. 5, 6.) 



Trophosome. — Stem fascicled, irregularly branched, becoming 

 monosiphonic towards the distal extremities of the branches. 

 Hydrothecae with a deep constriction in front at a short distance 

 below the margin ; margin with a broad angular lobe on each side, 

 and a long, strong, curved, spine-like tooth in front ; intrathecal 

 ridge well marked, situated at the junction of the middle and 

 posterior thirds of the hydrotheca- walls ; mesial nematophore 

 forming a broad strong process adnate to the hydrotheca as high 

 as tl)e constriction below the margin, and then becoming free 

 and attaining about the height of the distal end of the anterior 

 marginal spine ; lateral nematophores strong, cylindrical, attaining 

 the level of the points of the marginal lobes of the hydrothecae. 



Cronosome not known. 



Locality ? 



The present species attains a height of nearly 6 inches. The 

 hydrotheca, with its two-lobed margin and strong anterior spine- 

 like tooth, the deep constriction below the margin, and the very 

 broad and long mesial nematophore afford an assemblage of 

 characters by which this remarkable species may be at once 

 distinguished. It is probably correctly referred to HaUcornaria, 

 though in the absence of gonosome this determination cannot be 

 regarded as otherwise than provisional, 



Halicoenaeia coentjta, n. sp. (PI. XXIII. figs. 1-4.) 



Tropliosovie.- — Stem simple, monosiphonic, springing at short 



intervals from a network of creeping filaments. Hydrothecae 



deep, rapidly narrowing towards the base and with the axis 



directed obliquely forward; margiu with two broad, somewhat 



