Htuckfa'. — Aiieinoiic^ found in Neighbo2irhoo(l of Wellmgton. 371 



seen to be thrown into parallel ridges which lie close together, running round 

 the body of the animal like hoops round a cask. Each of these folds is 

 wrinkled or pleated, the pleats being so close together and so nearly in line 

 as to almost present the appearance of longitudinal ridges. The result is 

 that both in cross-section and in longitudinal section the wall presents the 

 appearance of being covered with numerous papillae, into which the mesogloea 

 runs, often branching or folding in them (Plate XIX, fig. 1). Occasionally 

 the folds grow together and fuse, so that here and there we have in the me- 

 sogloea pits lined with ectoderm (Plate XIX, fig. 2). In cross-sections these 

 appear as more or less circular spaces. The ectoderm peels off in the manner 

 described by McMurrich in his account of Leiotealia badia. It presents the 

 usual histological features. Nuclei are numerous, and crowded towards the 

 outer part, while below this the outlines of the cells form a network. The 

 fibrils of the nervous layer form a more or less continuous line. Nematocysts 

 are present in great quantities, and there is great development of large 

 gland-cells, some of which are lenticular, others pyramidal in shape. The 

 mesogloea presents a wavy appearance, and has a few large scattered cells. 

 Fine processes of the mesogloea project inwards, carrying the circular muscle 

 of the wall. This muscle is not. continuous all round the body, but is in 

 bands, which overlap each other. The actual endoderm of the body-wall 

 is thin, and does not present any unusual features. 



Tentacles. — These are arranged in three cycles — 10 in the first or inner, 

 20 in the second, 30 in the third. This arrangement gives the appearance 

 of their being placed in groups of six, thus ; : • Each tentacle is conical in 

 shape, and very stout. All the tentacles are equal in size. In colour they 

 are of a dull white, with a mauve tip. In a few specimens, which, it is 

 worth noting, were all obtained from Island Bay, the mauve tip w^as wanting, 

 and in these cases the longitudinal markings of the body-w^all appear to be 

 entire. One specimen had light-brown tentacles. There is a pore at the tip 

 of each tentacle. The tentacles of the first two cycles communicate with 

 the endocoeles, those of the third cycle with the exocoeles of the mesenteries. 

 There is a strong longitudinal muscle borne on numerous fine branching 

 processes of the mesogloea (Plate XIX, fig. 3). Outside this is the nervous 

 layer in the form of a distinct reticulum. The endodermal or circular 

 muscle of the tentacle is not particularly strong. 



Sphincter Muscle (Plate XVIII, fig. 2). — This is very strong, and endo- 

 dermal in character. It projects into the coelenterm, and forms a rounded 

 cord, easily seen by the naked eye in a dissection. With a good light behind 

 an expanded specimen the sphincter can be seen through the body-wall. A 

 transverse section of the sphincter presents the same pinnate appearance as 

 that described by McMurrich in the sphincter of L. hadia. The endoderm sur- 

 rounding it is thin. The muscular fibrillar are seen in cross-section as small 

 swellings on the sides of the branching mesogloeal processes. In a longi- 

 tudinal section of the sphincter we see the fibres of the mesogloea running 

 in wavy parallel lines, while beside them are the muscular fil)res with their 

 nuclei cut at various angles. 



Oral Disc. — The colour is reddish-brov,^n, marked in radiating lines by 

 the insertions of the mesenteries. The mouth is set on a darker-coloured 

 prominent peristome, round which is a depression. There are two siphono- 

 glyphs marked by pink tubercles. The structure of the disc recalls that 

 of the tentacles, except that the nervous and muscular layers are not so well 

 developed. 



