REPORT ON CORALS — HYDROCORALLIN^E. 73 



Soft structures of CryptoheUa pudica (PL IX.). 



Ccenosarc. — This differs in structure in no essential particular from that of Astylus 

 subviridis. Similar axial canal systems are present in the branches and similar surface 

 networks, but these latter are finer and more complicated in the present form than in 

 Astylus. The lid and its support consists of a reflection of the surface layer of ectoderm, 

 beneath which is a prolongation of the surface network of the ccenosarcal canals, and in 

 the thicker portion of the stem of the lid run abundance of prolongations of the deeper 

 and larger vessels (PL IX. L). Rounded nematophore sacs, closely similar to those of 

 Astylus subviridis, are dotted about over the upper surface of the lid, and, as in Astylus, 

 a single one of these bodies is placed at the margins of each cyclo-system over the 

 outer extremity of each pseudoseptum (PL IX. N N). The pigmented endoderm cells 

 are coloured brick-red as in Sporadopora dichotoma. 



Zooids. — The zooids of both kinds most closely resemble those of Astylus subviridis. 



Dactylozooids. — These are elongate conical in form, tapering to a point. Their 

 bases are attached as in Astylus subviridis. In retraction the part of them nearest the 

 base is doubled back in the wide slit-like chamber of the dactylozooid towards the 

 periphery of the cyclo-system, and then the remainder of the zooid is bent over in the 

 reverse direction and doubled down into the mouth of the gastrozooid (PL IX. D Z). 



Gastrozooids. — These are flask-shaped and closely similar in structure to those of 

 Astylus subviridis, being, like it, devoid of tentacles (PL XL fig. 1). The mouth appears 

 at the flat summit of the neck of the flask as a cruciform aperture. The cavity 

 of the zooid is lined with the usual gastric endodermal cells of elongate form, and the 

 layer formed by these cells becomes, as in the gastrozooids of Sporadopora dichotoma, 

 thinner as the base of the zooid cavity is approached. There is a thick investing 

 ectoderm layer in the upper part of the zooid, between which and the endoderm layer 

 is a well-marked layer of longitudinal muscular fibres, which fibres are, as in Sporado- 

 pora, continued for insertion along the main canal offsets of the base of the zooid 

 (PL IX. M). 



The gastrozooid sac is attached just beneath the origin of the neck of its flask-shaped 

 mass. The main canal offsets spring from the periphery of the rounded base of the 

 zooid, with a radiating disposition (PL XL fig. 1). They curve upwards to be distri- 

 buted as in Astylus subviridis. The calcareous wall of the upper chamber of the 

 gastropore lies in the interval between these canals and the outer surface of the sac of 

 the zooid. No canals spring from the under surface of the zooid. 



Gonophores. — A fragment of a male specimen of CryptoheUa, obtained off the 

 Japanese coast, was examined in a cursory manner, and it was seen that, at first sight 

 at least, it resembled Astylus subviridis in the structure of its gonophores. Unfortun- 

 ately it was mislaid, and I have been unable to find it again. 



(ZOOL. CHALL. EXP. PABT VII. 1880.) G 10 



