NO. 140). PARASITIC COPEPODS—CALIGID.F.— WTLSON. 573 



findW. (i; from tho polluck (/^/^/r•///^^s■ /v'/v;/.v), 12G()1>, 12<)25, W. 1, 5, 

 and 8; from the hake {Ur(yphijris c/nm), 12628, 12()40, W. 2 and 23; 

 from the hake {Uroj^kt/Gis tenn/'s)^ 6094, 6161, 6165; from the lumptish 

 {Cyclopterus lumpus)^ 12617; from the mackerel {Sconihcr t<conihrus)^ 

 12620, 12621, 12622; from the scup {Stenotonm.s chnjsops), 12630, W. 

 20; from the striped bass {Rocgux Imeatu-s), 12613; from the alewife 

 {Clujjea veimalis), 1262-4; from the sturgeon (Aclpenser sturio), 12623, 

 W. 21; from Acipenser hrcvlrostruin, 12610, 12615, 12618, 12629; from 

 the sting- ra}" {IJa-^i/atis centrura)^ 6188; from the skate {Rala hevi.s), 

 6163, 12608, 12633, 12637, 12642, 12643; from Bala oce/lata, 6065, 6104, 

 6112; from BaM erinacea,, 1399, W. 14 and 24; from the spiny dogfish 

 {Squalus aca/Uhias), 12639; from different sculpins, 8114; from the 

 whiting {MeiiticirrJiu.'^ mxatlli.^), 6164; from the shad {Alom mjudts- 

 .sl/iHf)j 12612; from the swordfish (X//>Aw/.s- (/la(lm.s),W. 12; from the 

 rudder lish {Kyphmas sectatrie)^ taken in floating gulf weed, W. 11; 

 from the sand shark {Caixlmrias littoralis),^^. 9; from the remora 

 {Reitiora remora)^ W. 13; from the crevalle {Oarafi,v c/h/s-os), W. 15; 

 from the cutlass lish {TriclitKrus lepturu.s), W, 19; from the sand launce 

 {Ainntodijtes ainerlGamiH)^ one unnumbered lot. There is also a single 

 specimen of the chalimus stage still attached to a small jSLonacantJuia 

 and numbered W. 20. Other specimens of the chalinuis are numbered 

 6110, 6148, 6191, and W. 1, From the surface were obtained lots 

 6097, 6197, 8110, 12614, 12616, 12619, and W. 3, some of which con- 

 tain several specimens. The National Museum also possesses a fine 

 series of specimens from the Durham coast, England, contributed ])y 

 the Rev. A. M. Norman, numbered 12906. These have been taken as 

 the types of the. species, and with them all the American forms ha\'e 

 been carefully compared. 



CALIGUS MUTABILIS, new species. 

 Plate VIII, fig. 2 in the text. 



Female. — Carapace about three-sevenths the entire length, as long- 

 as w ide, not narrowed anteriorly. Frontal plates well defined, but less 

 than half the width of tlie carapace; lunules large, circuhxr, and pro- 

 jecting. Posterior sinuses wide and slightly inclined away from the 

 central axis. Median lobe much less than half the entire width and 

 projecting only a little beyond the lateral lobes; the latter l)lunt and 

 well rounded (fig.. 90). 



Thoracic area medium size, the anterior groove almost a perfect 

 s(Mnicircle. Free thorax segment short and narrow, al)out one-fourth 

 tiie width of the carapace, and contracted into a much narrower neck 

 just in front of the bases of the fourth legs. Genital segment very 

 variable, according to the age of the individual as well as the develop- 

 mental stage of the eggs. In young females and in the adults before 



Proc. N. M. vol. xxviii — 04 37 



