Plate VI. 

 Pourtalesia laguncula Ai.. \i,. Pourtalesia carinata Ai,. Ag. 



The aiubulacral system coloured. 



Fig. 37. Tile skeleton of 1'. lanuTieula, ventral view, p. 17. 



Fig. 38. Tlie skeleton of P. lagnncnla, another specimen, \eiitral view. 



Fig. 39. The sub-oral region of the same. 



Fig. 40. The suli-oral region of the specimen (ig. 'M . 



Fig. 41. A peristomal pedicel and spherid, of the same. 



Fig. 42. The sub-oral area of P. carinata. 



Fig. 43. The same, from another specimen. 



Fig. 44. Peristomal part of the same area, from the specimen fig. 42. 



Fig. 45. The infra-frontal recess, seen from the peritoneal cavity; left view. 



Fig. 46. The involuted part of the labial region. 



