42 PERCY SLADEN TRUST EXPEDITION 



Costse prominent, with short spines. Columella openly trabecular, intermediate between 

 C. suvadivw and C. serailia, rods hardly visible. 



Polyps. (1) Secondary entocoelic tentacles present. (2) Each tentacle with three 

 or four sub-terminal batteries. (3) Entocoelic pleats somewhat constricted at their bases, 

 arranged close together, best developed in the outer half of width of primary mesenteries ; 

 pleatal region of mesoglsea thinner than in C serailia. (4) Endoderm thickening con- 

 siderably from skeletal attachments of primary mesenteries to storaodseal attachments of 

 same. (5) Endoderm over stomodeeum thick. (6) Rudimentary filaments on secondary 

 mesenteries. 



Remarks. A. Polyps. Both granular and mucous vacuoles are abundant in the 

 ectoderm of the oral-disc and edge-zone ; sometimes the granules appear scattered in the 

 ectoderm ; between batteries granular vacuoles are conspicuous. Nematocysts I are 

 closely packed in all the batteries ; a few II h ones are also present in the terminal 

 batteries ; only nematocysts II and III have been observed in the mesenterial filaments, 

 some of the latter with partly discharged threads. The stomodseal ridges are somewhat 

 more thickened than in C. serailia. The endoderm is more vacuolated than in that 

 species, especially in the tentacles and primary mesenteries ; it is comparatively thin in 

 the oral-disc, edge-zone and upper half of the column-wall. Below the enterostome the 

 mesenterial endoderm is four or five times thicker in the inner half of the mesentery than 

 in the outer half, where the protoplasm is reduced to mere strands. Ova were present in 

 one polyp. 



Polyps examined, eight : three* from one specimen, three from a second specimen 

 (both Red Sea), twot from a third specimen (Ceylon). 



B. Corallum. Forskal's original of Madrepora chalcidicum is missing from the 

 Copenhagen Museum. I have retained his specific name, since it is not used for any other 

 species of corals and since my type specimens are similar to Klunzinger's figured example 

 (9x6 cm.) of Cyphastrea chalcidicum. 



Milne Edwards and Haime have referred three large specimens from the Red Sea to 

 SolenastrcBa heniprichana (two of them measuring 23 x 15 x 14 cm. and 21x18x13 cm. 

 respectively), resembling specimen no. 5 on p. 46 ; many of the corallites are arranged close 

 together and project like cylinders, a few of them being giant ones ; only in a few corallites 

 do all the secondaries meet the columella. These authors have assigned seven specimens 

 from the Red Sea to Solenastrcea gihhosa, three of them being large (23 x 15 x 14 cm., 

 20x10x10 cm. and 14x14x5 cm.), which are identical with many of my examples of 

 C. chalcidicum. Another specimen from the Red Sea named Solenastrcea chalcidicum 

 also comes here. Solenastrcea hournoni is represented by four small specimens from 

 Antilles (the largest measuring only 9x9 cm. ), approaching the present species ; a few 

 giant corallites are present on them. Solenastrcea bowerbanki, Ed. and H., is missing from 

 the Paris museum ; judging from Milne Edwards and Haime's description it comes 



* One of these is a giant-polyp with twelve couples of primary and eight of secondary mesenteries, the 

 former bearing ova. 



t In these polyps the stomodseum was less wide, its wall being deeply grooved at the mesenterial attach- 

 ments. The entocoelic pleats were somewhat thinner. These differences are due to the sudden shrinkage 

 of the tissues, as doubtless the specimens were not fixed or preserved properly. 



