Cyathocormus mirabilis n. g., n. sp. 5 



very shallow longitudinal depressions separating as many slightly 

 elevated longitudinal zones upon which double rows of very short 

 branchial siphons are placed. The inner surface has a number of 

 deep longitudinal furrows corresponding to the shallow depres- 

 sions on the outer surface. In the ridges separated by them the 

 dark coloured contents of the intestines look conspicuously 

 through the test and bod}^ wall. The stalk is shorter than the 

 head, columnar in shape, and is dilated at the lower end to form 

 the base of attachment. 



Size — head 18 — 22 mm. in length and 15 — '21 mm. in width; 

 the stalk about 12 mm. in length and 4 — 5 mm. in diameter. 



The test is soft, gelatinous, and perfectly transparent in the 

 head, and considerably harder and more or less opaque in the 

 peduncle. 



The zooids are of moderate size and are entirely imbedded in 

 the common test. They are 3 — 4 mm. in length and about IJ 

 mm. in greatest breadth. The body is divided, though not very 

 distinctly, into thorax and abdomen, the latter provided with a 

 long vascular appendage. 



T]ie mantle is very thin, muscle fibres being found only in the 

 anterior region where they form a sort of sphincter around the 

 branchial aperture. 



The Irœnchial sac is well developed but delicate. The trans- 

 verse vessels are narrow and are all of the same size. The stig- 

 mata are very long and narrow with rounded ends. 



The endostijle is consj^icuous. It is plicated dorso-ventrally 

 through the greater part of its length. 



The dorsal lamina is represented by three short pointed 

 languets projecting from the dorsal parts of the transverse 

 vessels. 



The tentacles are usually sixteen in number. Four are long 

 and meet in the centre of the branchial aperture when laid flat; 

 four others alternating with these are somewhat shorter, while 

 the remaining eight are onl}^ half as long as the former. 



The dorsal tubercle is very prominent, being unusually large 

 in proportion to the size of the branchial sac. The aperture is a 



