NO. U2S0. THE NEW CUI'EPOD FAMILY SPHYKIWAE—V.ILkiON. 599 



by two crescentic pads; rudiments of first and second antennae; a 

 retractile mouth tube with rudiments of one pair of maxillae. Male 

 unknown. 



2'ype of the genus. — Periplexis lohodes^ monotypic. 



(IlepiicXe'^Y;?, entanglement, alluding to the twisted neck.) 



PERIPLEXIS LOBODES, new species. 



Plate 59, figs. 77-80. 



Uoiit and record of specimens. — A single female with empty ^gg 

 cases was obtained by the Bureau of Fisheries steamer Albatross off 

 the coast of New Jersey in 1883 from Ale/pocejyhalus agassisii, a deep- 

 sea fish captured at a depth of 1,000 fathoms. The head and neck of 

 the parasite were buried in the flesh of its host alongside the dorsal 

 fin. This female has received Cat. No. 49757, U.S.N.M., and becomes 

 the type of the new species. 



Specific characters of female. — In addition to the generic char- 

 acters already given the cephalothorax is a little Avider anteriorly 

 and the truncated anterior end is curved over ventrally. The two 

 excellent figures drawn by A. H. Baldwin give a good idea of the 

 very complex tAvi sting of the neck and its armature, which nre so 

 intricate as to baffle any description. None of the processes or horns 

 are branched, but some of them reach a length of 5 or G mm., and 

 they are all, as well as the neck itself, covered Avith a thick chitin 

 skin. Behind these horns the neck enlarges gradually to a diameter 

 of 3 millimeters and joins the trunk in line with the axis of the 

 latter. The outline of the trunk is that of an acorn, the sides nearly 

 parallel, contracted to the diameter of the neck where it joins the 

 latter, and with rounded posterior corners. The width is three- 

 fifths and the thickness two-fifths of the length; the surface is 

 smooth and shiny save for the rows of depressions; dorsally there 

 are seven of these pits in a row, but ventrally there are four. 



The genital processes are split ventrally into three lobe?, which 

 overhang the bases of the egg strings. The egg cases are empt}', 

 but one of them is entire save for the perforations through which 

 the larvae escaped, thus giving the size. The abdomen is relatively 

 very small and thoroughly fused with the trunk. The posterior 

 processes are unlike anything that has ever been reported in tha para- 

 sitic copepods. Where the process is attached it is narroAved into a 

 short, threadlike neck; this enlarges abruptly into three large lobes 

 whose adjacent surfaces are pressed together and flattened; each 

 lobe is two-fifths as wide and the three together are half as long as 

 the trunk. 



The two crescentic pads form a thickened rim around :he trun- 

 cated anterior end of the head, their bluntlv rounded ends meetins: 



