600 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.55. 



dorsally and ventrally on the midline. The first antennae are small 

 spherical knobs on the dorsal surface of the head, behind the bases 

 of the second pair. The latter are more or less spherical and stune- 

 what elongated along the ventral surface, and do not show anv 

 chelate processes. In front of the bases of these antennae is tlie 

 mouth tube, which is raised a little above the surrounding surface 

 and carries on its sides a single pair of maxillae in the form of small 

 processes tipped with a spine. 



The whole structure of the head is so blind that if it were not for 

 the suggestion obtained from a study of the immature specimens of 

 Sphyrion lumpi, and the other genera here presented, it would be 

 almost incapable of interpretation; but analogy leaves little room 

 for doubt. 



Color (preserved material), cephalothorax and posterior processes 

 a clear yellow ; neck cinnamon brown ; trunk dark gray. 



Total length, including posterior processes, 60 mm. Cephalotho- 

 rax 9 mm. long, 4 mm. wide. Neck 3 mm. wide posteriorly. Trunk 

 25 mm. long, 15 mm. wide, 10 mm. thick. Posterior processes 12 mm. 

 long, 6 mm. wide. Egg strings 40 n:im. long, 5 mm. wide. If the 

 neck and cephalothorax were straightened it would add 15 or 20 mm. 

 to the length. 



(Xo^ojStq?, lobed like a pod, alluding to the posterior processes.) 



Remarks. — In spite of the fact that there is but a single specimen, 

 this new species presents much of interest. It can be recognized at 

 once by the posterior processes and the intricately twisted neck. 

 The latter furnishes new evidence of the extent to which the burrow- 

 ing and anchorage of the parasite in the tissues of its host can 

 modify its morphology. In the other genera we have found all kinds 

 of processes and horns. Here there is not only an extra profusion of 

 anchor processes, but they are combined with flexures and foldings 

 of the neck itself. Nothing short of a charge of dynamite could ever 

 loosen this parasite's hold upon its host. In the posterior processes 

 an increase of surface in contact with the water is obtained not b\ 

 branching nor by the attachment of numerous cylinders or cones, as 

 in other genera, but by a large increase in the diameter of the process 

 itself. Since there was but a single specimen, nothing could be 

 ascertained with reference to the internal anatomy ; but the presence 

 of the rows of pits on both dorsal and ventral surfaces proves the 

 existence of dorsoventral muscle bundles similar to those in the other 

 genera. Accordingly, we may assume that there is a corresponding 

 similarity in other details also. 



