176 



WILSON, 



[Vol. I. 



one of the results of further investigation in the Asiatic North 

 Pacific. 



Thalassema erythrogrammon Max Miiller. — I obtained a 

 specimen of this Thalassema through the kindness of Dr. E. 

 A. Andrews of Johns Hopkins University. 



It was taken at Green Turtle Cay, off Great Abaco Island, 

 the Bahamas, in the summer of 1886, and when alive was of 

 a flesh color with reddish longitudinal stripes, the proboscis 

 lighter in color, the papillae whitish. The body was raised 

 into longitudinal ridges between the muscle bundles whose 

 prominence varied with the degree of contraction. The speci- 

 men was hardened in Perenyi's fluid, and yet the muscle bands 

 show a decided pink-brown color at the present time and stand 

 out very distinctly, as can be seen in the photograph (Fig. 5). 



It was excellently preserved in a normal condition and meas- 

 ures 16 cm. in length (including the proboscis, 3 cm. long) and 

 2.4 cm. in greatest diameter. Body spindle-shaped, with bluntly 

 rounded ends, and after preservation not perceptibly flirrowed 

 by the longitudinal muscle bands. Papillae in dense placques 

 at the posterior end of the body ; no smooth area in the imme- 

 diate vicinity of the anus. Longitudinal muscles in sixteen 

 bands about 1.5 mm. wide, with interspaces 4.5-7 mm. wide at 

 the center of the body, except the two bands on either side of 

 the ventral mid-line which are close together. 



Proboscis so fleshy as to be nearly a solid cylinder, i cm. in 

 diameter at the base, thus bringing the mouth to the extreme 

 ventral surface ; less fleshy and not broadened toward the tip. 



The two setae were so far withdrawn into the thick skin as 

 to be wholly invisible from the external surface, but could be 

 all the more plainly seen on the interior. 



The specimen proved to be a ripe male, and the three pairs 

 of nephridia were enormously swollen and packed with sperm. 



They increased in size from in front backward, the respective 

 lengths being 3.2, 4.5, and 8.2 cm. The two posterior pairs 

 were constricted at intervals and looked much like a string of 

 sausages ; the anterior pair opened 3 mm. in front of the ven- 

 tral setae, and all three pairs were furnished with spirally «coiled 

 internal openings. 



