Zoophytes. 203 



believed them to be part of the coral itself, and called a specimen of 

 Astraja which was full of them, Madrepora polygama (Amoen. Acad. iv. 

 250, t. 3, f. 15), denying at the same time that they could be Lepades! 

 because of the absence of the valves, the small size of the holes, and 

 the surface of the cavity being rayed. Savigny, in the large work on 

 Egypt, appears to have properly understood their structure : since 

 his time the various kinds have been minutely examined, and placed 

 in different genera. Those inhabiting stony corals form a tubular 

 sheath or base, as it is called, which is elongated at the top by the secre- 

 tion and deposition of fresh shelly matter on the edge of the tube, as 

 the coral grows : those that live in sponges form hemispherical bases, 

 which are enlarged in the same manner : and those which fix them- 

 selves in the stems of Gorgonise form a slipper-shaped base, to enable 

 them to clasp the thin stem, and at the same time maintain a suffi- 

 ciently erect position to allow the animal freely to collect its food. 



In the instances cited the coral has followed its usual course, and 

 the animals have only taken up their abode in its substance; but 

 Spengler long ago described a coral under the name of Madrepora 

 cochlea, which appears to be a Cyathophylla, whose form has been 

 modified by some worm taking up its abode in its base, and forming 

 within the lower side of the coral a cylindrical spiral cavity. The 

 base of the coral is slipper-shaped, with a large round hole com- 

 municating with the tubular cavity near the projecting part of the 

 slipper. The star is more or less irregular, formed of many unequal 

 rays, with a compressed perforated centre ; besides this hole there 

 is a series of minute pores on the upper surface of the margin, and of- 

 ten some others in the centre of the base, which appear to communi- 

 cate with the tubular cavity. I have lately received from China, with 

 the specimens above described, another species, agreeing with the for- 

 mer in most particulars, but differing from it in the coral being more 

 solid and hard, and the whole of its surface being covered with con- 

 tinued longitudinal ridges, with finely crenulated edges, extending 

 from the edge of the star to a little within the margin of the flat base. 

 The star is formed of more lamina, which have a number of shorter 

 columnar processes placed between them, especially near the central 

 depression. The large hole enters obliquely, and is furnished with a 

 regular shelly sheath (not found in the other species), and the holes 

 communicating with the tube are only to be observed on the hinder 

 half of the erect sides of the coral, and not at all on the base. I would 

 propose to call this Cyathophylla Spengleri, in honour of N. Lorenzo 

 Spengler, the excellent Danish conchologist who first described the 



