CECSOPS LATRKILL1I. 99 



both rami two-jointed, except in the fourth pair, the 

 rami of which are both uniarticulate. The outer 

 ramus in the first three pairs stouter than the inner, 

 and the first joint larger than the end one, and 

 carrying on its outer distal angle a short but stout 

 spine. The outer ramus in the fourth pair small, 

 but the inner considerably expanded and so also is 

 the basal joint of this pair. Caudal rami short and fur- 

 nished with a few apical setse. Length about 25 mm. 



Male. — The male differs from the female in being 

 smaller, and it also wants the large posterior dorsal 

 plates of the genital segment. Some of the thoracic 

 legs are also slightly modified. Length about 16 mm. 



Habitat. — Parasitic on the gills of the short sun-fish, 

 Orthagoriscus mola. Recorded from many parts of 

 our coasts. South of Ireland, Dublin, Coast of 

 Antrim, &c. (G. J. Allman—Aug. 1848, B. Ball, W. 

 Thompson, — see Baird, p. 293). Polperro (A. M. 

 Norman). Plymouth (Bassett- Smith). Falmouth 

 (Codes). Solway, Jan. 1857 (J. Stewart). Firth of 

 Forth (A. Scott). Lerwick, Shetland; Mallaig, W. 

 coast of Scotland (T. Scott). On a short sun-fish 

 captured off Berry Head (Major E. V. Elwes). 



In the female the egg-strings are very long, but instead of 

 projecting externally they are twisted upon each other in 

 numerous loops and lie concealed in the hollow space 

 between the abdomen and the large buckler-shaped last 

 segment of the thorax. The specimens we have seen have 

 all been obtained from the gills of the short sun-fish, where 

 large numbers may sometimes be found crowded together. 

 The general colour of the parasites is yellowish, but the 

 colour of the strong terminal hooks of thtf maxillipeds is 

 dark brown, nearly black. 



Cecrops latreillii appears to be one of the most widely 

 dispersed species of the Caligidaa; in addition to the 

 European records of this parasite, it has also been reported 

 from both ,the xVtlantic and Pacific coasts of North America, 

 and G-. M. Thomson states that several specimens were 

 obtained from the mouth of a sun-fish (Orthagoriscus mola) 

 which was caught- in Otago Harbour (Otago Museum).* 

 * 'Trans. N. Z. Institute/ vol. xxii (1889), p. 362. 



