TUNICATA. 327 



Branchial Sac of a dark brown colour, with four folds on each side. About six 

 internal bars on the fold and eight rows of stigmata in the interspace. There are 

 three or four narrower transverse vessels between much wider ones. The meshes are 

 nearly square, with 3 or 4 stigmata in each (fig. 31). 



Dorsal Lamina a plain membrane. 



Tentacles at least 30 in number, large, with occasional smaller ones (fig. 32). 



Dorsal Tubercle simple, horse-shoe-shaped, with the opening anterior and the horns 

 not coiled (fig. 29). 



Alimentary Canal dark brown, anus surrounded by about eight finger-like processes 

 (fig. 28). 



Gonads, numerous polycarps and endocarps, all of a very dark brown colour, partly 

 sunk in mantle. 



Locality. (1) Jokkenpiddi Paar, Gulf of Manaar, 10 fathoms, two specimens; 

 (2) Station LXIX., Chilaw Paar, 11 fathoms, one specimen. 



Two larger and several smaller specimens of a Crenella were embedded in one test. 

 Tbis species is dedicated to Sir William Twynam, of Jaffna. 



Polycarpa manaarensis, n. sp. Plate VI., figs. 1G to 22. 



External Appearance. Somewhat quadrate in shape, with the apertures on two 

 equal projections, giving the anterior end a cleft appearance (fig. 16). Surface 

 corrugated and encrusted with sand and shell fragments. Colour, dark brown on 

 surface, with a pearly lustre inside ; size about 4 centims. x 3 "5 centims. 



Test leathery, hard and stiff. In section it is seen that the sand-grains are 

 embedded in, as well as attached to, the test. 



Mantle thick, opaque, ruddy brown. 



Branchial Sac with four folds on each side. There are about nine bars on a fold 

 and six in the interspace. The transverse vessels are of three orders with still smaller 

 ones crossing the stigmata frequently and irregularly (fig. 22). The meshes are nearly 

 square and have about four stigmata each. 



Dorsal Lamina a narrow plain fold (fig. 21). 



Tentacles placed a long way in front of the peripharyngeal band (figs. 17, 20); 

 about 40, larger and smaller alternately. 



Dorsal Tubercle a widely open horse-shoe, with the opening anterior and the horns 

 not turned in (figs. 18, 19). Pre-branchial zone pigmented. 



Alimentary Canal a wide loop, stomach globular. 



Gonads, many large rounded polycarps sunk in the thick mantle. 



Locality: (l) Station LXIL, Periya Paar, 13 fathoms, one specimen; (2) Station 

 LXVL, off Mutwal Island, 10 to 35 fathoms, one specimen ; (3) Jokkenpiddi Paar, 

 Gulf of Manaar, 10 fathoms, one specimen. 



Specimens of Synalphmus comatulorum were found in either the branchial sac or 

 the atrium of all the specimens. 



