PHILORTHBAGORISCUS SEKRATUS. . ] 05 



Distribution. European seas. Atlantic coast of 

 North America (G. B. Wilson). 



The species will he found recorded under the Rev. A. M. 

 Norman's MS. name Monima fimkriata, in the appendix to 

 Smiles' ' Life of Thomas Edward ' (p. 437, 1876), as one of 

 the many creatures that keen-sighted naturalist added to the 

 fauna of Scotland. The same species was also found on a 

 short sun-fish captured by Mr. C. Beadle, off Berry Head, in 

 August 1908, and presented by him to the Torquay Natural 

 History Society. On this sun-fish Major E. Y. Elwes obtained, 

 among* other interesting parasites, four female and one male 

 Philorthragoriscus serratus which he very kindly permitted us 

 to examine. 



Family in. DICHELESTIID^E. 



Body generally elongated, head moderately small. 

 Free thoracic segments usually simple, but sometimes 

 provided with dorsal plates. Abdomen usually small 

 or rudimentary. 



Antennules slender, moderately elongated, and com- 

 posed of several joints, rarely short with, two or three 

 joints. Antennae armed with terminal claws and 

 generally projecting more or less beyond the edge of 

 the cephalothorax. Mouth parts somewhat similar to 

 those of the Caligidae. Thoracic legs usually four 

 pairs, frequently short, stump-like or suppressed, or 

 with the posterior limbs transformed into lamelliform 

 plates. Eye single, median, or absent. Genital organs 

 as in the Caligidae. Sexual differences not very 

 marked, but the male usually smaller than the female, 

 and both for the most part capable of a certain amount 

 of locomotion. 



Genus 19. DICHELESTIUM Hermann, 1804. 



Head obtuse, body elongated, consisting of four 

 distinctly-articulated segments without dorsal plates. 

 Genital segment tolerably elongated. Abdomen small. 

 Caudal rami not very prominent. 



Antennules slender and composed of eight joints. 



