NO. 1504. A MERK'AN J' J EASITIC COPEPODS— WILSOX. 718 



And on the next page he adds: '' Host: ' Shark,' Atlantic and Indian 

 oceans." 



This hist must have been taken from the hibols of the British 

 Museum specimens, for Steenstrup and Liitken distinct!}' state that 

 their specimens were taken ''probabl}' while swimmino- freelv at the 

 surface.***' 



If Bassett-Smith's observation regarding the "large number of speci- 

 mens, .some with external ovaries attached," in the British Museum 

 be correct, there is a probabilit}- that the genus is valid. But we can 

 not be certain until the females are described; for the present, there- 

 fore, both the original species and the new one here described are to 

 be accepted provisionally. 



DYSGAMUS ARIOMMUS, new species. 

 Plate XX, li^H. (52-70. 



JIalt. — Carapace 0.6 of the entire length, ovate, considerablv wid- 

 ened and squarel}' truncated posteriorly. Frontal plates prominent 

 and distinct, without lunules, but with a broad and shallow incision at 

 the center. Cephalic area divided by a trans\'erse groove which starts 

 from the lateral groove on either side at a point opposite the eyes, 

 and then divides, one-half passing* in front of the e^^es and the other 

 half behind them, in the form of two semicircles of different diam- 

 eters, the posterior one being* the smaller. Thoracic area three-hfths 

 of the width of the carapace, but short, with nearly straight and 

 parallel sides: square!}' truncated both anteriorly and posteriorly. 



Lateral areas narrow and elongate, showing clearly the separation 

 between the head and first thorax segment; posterior lobes, with 

 bluntly- rounded ends just reaching the posterior margin of the thor- 

 acic area. Tlie narrow and tapering lateral lobes which extend from 

 the sides of the second segment Ijackward inside of, and parallel to, 

 the carapace lobes are not as completely fused with the latter as usual, 

 but are separated from them by very narrow and slit-like incisions, 

 which extend inward halfway to the anterior margin of the second 

 segment. The tips of these second segment lol^es do not quite reach 

 the posterior margin of the third segment, which is considerably nar- 

 rower than the second. 



The lateral lobes of the third segment are broadly triangular and 

 extend diagonally outward and backward over the bases of the third 

 legs. The fourth segment is narrower than the third with prominent 

 and well-rounded sides. Genital segment 0.175 of the entire length, 

 of a plump, l)arrel shape, with squarely truncated ends; no rudimentary 

 legs visible. 



"Bidrag til Kundskabom det aabne Havs Snyltekreljs og Lernjeer, 1861, p. 368. 



