RHIZOCEPHALA — REINHARD 303 



The mantle and visceral mass, in general structure, are like those of 

 Peltogaster paguri and exhibit no unusual features. The mesentery 

 is broad, about equal in width to the visceral mass, and extends 

 from one end of the sac to the other. At the base where the two 

 arms meet there is an extension of the mesentery towards the right 

 to connect with the stalk. The visceral mass accompanies the mesen- 

 tery to its termination. 



The testes are exceedingly small, rounded bodies set close to the 

 stalk. They measure only 35 to 40 microns in diameter. The 

 straight and comparatively long vasa deferentia pursue an upward 

 course away from the stalk along the surface of the basal extension 

 of the visceral mass. Then- length is about 250 microns. 



Tlie colleteric glands are located near the anterior end of the sac, 

 with the left gland slightly in advance of the right. In a cross 

 section of the animal the gland appears as an elliptical mass com- 

 prising a single canal surrounded by several layei-s of cells. Its 

 depth is 60 to 80 microns and its extent in a doreoventral direction 

 is about 150 microns. 



Genus Tortugaster Reinhard 

 Tortugaster fistulatus Keinhard 



Figure 4,c 



Tortugaster fisitdatus Reinhard, 1948, pp. 33-37, fig. 1 (external appearance, 

 internal structures), fig. 2 (transverse section), fig. 3 (vas deferens). 



MATERiAii examined: South of Cay Sal Bank, north coast of 

 Cuba, Atlantis Station 2987, lat. 23°22' N., long 79°53' W., 280-300 

 fathoms. Mar. 13, 1938; one specimen on Munidopsis spinifer (A. 

 Milne Edwards). Harvard-Havana Expedition. MCZ 11755. 



East of St. Augustine, Fla., Atlantis Station 3780, lat. 30°27' N., 

 long. 79°52' W., 250-265 fathoms, Feb. 24, 1940; one specimen on 

 Munidopsis bahamensis Benedict. MCZ 11734. 



These are new locality and new host records for a species that has 

 previously been known only from the type specmiens found on 

 Munidopsis robusta A. Milne Edwards, off Tortugas, Fla. In their 

 attachment and orientation with respect to the host and in their 

 external appearance these examples of T. Jistulatus agTee with the 

 type. The specimen on Munidopsis spinifer measures 6 mm. in 

 length and 3 mm. in width and is a mature animal with eggs present 

 in the mantle cavity. The parasite on Munidopsis bahamensis is 

 also fully developed and differs from the other only in size. Its length 

 is 8 mm. and width 4.5 mm. Because of then- poor state of preserva- 

 tion these animals were not sectioned. They are the specimens 

 ("abdominal parasites") mentioned by Chace (1942, pp. 89, 91) in 



