212 MONOGRAPH I A 



nellus cristatus), and Shaw and Albin, if their figures are 

 of the same insect, give the Cormorant. 



6. COLPOCEPHALUM PICEUM. Denny. (Louse of the 

 Sandwich Tern.) 

 Plate XVIII. Fig. 4. 



Deep liver-colour, almost black, very smooth and shin- 

 ing, large and punctured ; pro thorax sub -quadrate. 



Head large ; clypeus broad and rotundate, with three 

 foveolse, orbital sinus very deep, vertex concave and punc- 

 tured, occiput truncate, with black clypeal, orbital and basal 

 spots like the preceding ; eyes prominent ; antennae dusky, 

 the first joint thick, second very small and cylindrical, third 

 ob- conical, fourth conical ; prothorax nearly as wide as the 

 head, sub -quadrate, lateral margin produced anteriorly on 

 each side, a transverse and longitudinal depression in the 

 centre, somewhat resembling the letter T; mesothorax very 

 short, transverse ; metathorax transversely sub- conical, base 

 truncate ; abdomen ovate, rather paler than the head and 

 thorax, with black lateral fasciae to each segment, except the 

 last three ; legs pitchy, rather thick ; anterior femora not 

 involute. Length 1. 



The only specimen of this species which I have seen was 

 forwarded by Mr. Thompson, who took it from the Sand- 

 wich Tern (Sterna Cantiaca). It might on first sight be sup- 

 posed to be only a dark variety of the preceding, but when 

 the two insects are placed together, there can remain no 

 doubt of its specific difference, the larger size of the head, 

 different form of prothorax and antennae, and intensity of 

 colour are very conspicuous, the lateral patches can only be 

 seen by transmitted light. 



