CRETACEOUS CRUSTACEA. 269 



sentative of the internal parasitic genus Bophijrus, which attaches 

 itself to the internal gills of many Crustacea at the present day, 

 manifesting its presence by the like external symptom. 



Notopocorystes Carteri (M^Coy). See Plate, fig. 3. 



Desc. Carapace elongate, trapezoidal; greatest width (a little 

 behind the mesial furrow) at the posterior of the three large 

 antero-lateral tubercles of the margin ; gently convex, de- 

 pressed. Nuchal furrow obscured by the map-like marking 

 on the anterior part of the carapace, but it is moderately deep 

 and extends from between the two posterior marginal tuber- 

 cles, with an irregular curve backwards, rounding at a mode- 

 rate angle under the posterior gastric lobes. Gastric region 

 very large; meso-gastric lobe forming a very narrow linear 

 ridge, nearly from the nuchal furrow quite to the extremity 

 of the rostrum, completely dividing the great proto-gastric 

 lobes ; it is destitute of the large tubercles on this part of the 

 other species, the granulation being almost invisible to the 

 naked eye, except along its edges ; its posterior end is con- 

 fluent with the tw^o transversely rounded, subtrigonal, small 

 posterior gastric lobes, which also form nearly smooth ele- 

 vations immediately in front of the nuchal furrow ; the an- 

 terior gastric lobes (coinciding with the origin of the anterior 

 gastric muscles) form narrow obliquely elongated elevations, 

 running along the front margin, from the inner notch of the 

 orbit to the rostrum, along which their anterior ends abruptly 

 turn, rendering it trifid, including the point of the meso- 

 gastric lobe, which they resemble in being nearly smooth and 

 being edged with a line of slightly larger granules under the 

 lens ; proto-gastric lobes very large, ornamented on each side 

 with a trident-shaped group of three elongate elevated lobes, 

 nearly equidistant in front, and converging towards the small 

 posterior gastric lobes behind, the outer lobe of the three 

 usually disconnected at th« base from the conjoined inner 

 two ; it has also a small round elevation immediately anterior 

 and external to its anterior end ; no distinct orbital regions, 

 but the outer angle of the very large orbits forms the anterior 

 of the three lateral tubercles ; the very small triangular hepatic 

 regions, coinciding with the middle lateral tubercle, have also 

 a small elevated subtrigonal lobe close to the margin ; ante- 

 rior branchial region (or space between the nuchal and meso- 

 branchial sulci) forming a broad oblique band on each side, 

 extending from each side of the posterior lateral tubercle to 

 the uro-gastric region ; it has one small smoothed elevation at 

 the lateral tubercle, immediately within and in front of which 



