200 



PROCEEDINGS OF THE ACADEMY OF 



[1879. 



DESCRIPTION OF A NEW BRANCHIPOD. 



BY JOHN A. RYDER. 



Upon examining a pair of Branchipods which were kindly 

 handed me by Mr. D. S. Holman, and which had been collected 

 near Woodbury, N. J., I find them to be a form hitherto unde- 

 scribed. I accordingly propose a name for the species. 



Streptocephalus sealii, nov. sp. 



In form and size this species resembles S. lorvicoriiis, Waga, 

 but the third joint of the second antenna differs from that species 

 in the details of its structure, and the ovigerous sacs of the fe- 

 males are not blue as in Waga's animal. The inner branch of the 

 terminal joint of the male claspers is the shortest instead of the 

 longest, as in S. torvicornis ; at the interior anterior margin of. the 

 short branch, there are two unequal lobes, extending forwards 

 and lying flat against the laminar posterior border of the anterior 

 branch ; at the lower posterior angle of this lamina, or blade of the 

 forward branch, there is a well-marked, somewhat falcate process, 

 which fits between the lower lobular process of the posterior 

 branch and its scythe-shaped lower extremity. The anterior 

 branch then crosses the posterior at nearly right angles, and for 

 about a third of its length maintains a pretty uniform thickness, 



and is straight, when it suddenlj' swells 

 and bends forwards, and as suddenly con- 

 tracts, and tapers for its remaining two- 

 thirds, ending in a slender, slightly-curved, 

 pointed extremity. The first joint is long 

 and robust, and from its apex external^, 

 the cylindrical, curved, antenniform organ 

 arises, which is about as long as the fili- 

 form first antennas. The second joint is 

 very tortuous, and is strongly bent and 

 twisted upon itself. The third joint, which 

 bears the complex terminal appendages, is 

 wide; the appendages close against each 

 other like the blades of a scissors, whilst 

 the processes of their opposing margins interlock as has been 

 already described, and as can be fully understood bj r reference to 



