440 ME. p. W. BASSETT-SMITH ON [Apr. 18, 



well demonstrated by Hesse; and the very interesting metamor- 

 phosis that the Lerncea branchialis goes through before becoming a 

 fixed inert sac has been beautifully worked out by C. Claus, who 

 has shown that copulation takes place when the animals are of 

 very small size, the maturity of the ovules keeping pace with the 

 increased growth of the female. The young unattached forms of 

 this species have been taken in the tow-net by Mr. I. C. Thompson 

 on more than one occasion ; the juvenile conditions of other genera 

 have been taken free, having been described as Baculus and 

 Hersellia, which are probably the young of Penella. 



In the family Ergasilidse (p. 441), the genus Thersites Pagenst. 

 does not appear to me to be distinct from Ergasilus, the only 

 species of the former having been described from the gills of 

 Gasterosteus aculeatus, from which, too, a species of the latter genus 

 is taken ; I have therefore united them together. 



In the family Caligidse (p. 444), the number of described species 

 of Qaligus is very large, and some of them have undoubtedly been 

 known by many names ; these I have endeavoured to place in their 

 ■ proper places. The genus Papidina of Van Beneden has been 

 relegated to Lepeopliihei7^us, from which it has no marked differ- 

 ences ; his genus Oalina has been established, but the specimen 

 described by him as Caligeria belongs to the old-formed genus 

 Alebion of Kroyer. The Lepeophtlieirus huttoni of Thomson, taken 

 in New Zealand, a specimen of which he has been good enough to 

 send me, should be placed with Oloiopotes Stp. & Liitk. Examples 

 of the same species are present (unnamed) in the British Museum, 

 taken at Madras. The genus Nogagus has been entirely left out, 

 as it contains only male forms of other genera. The name Peris- 

 so2ms has been retained for Dana's Lepidopus, which is already in 

 use, and Van Beneden's Ghlamys is of more recent origin. 



In the family Dichelestiidae (p. 468), the genus Epacliilies has 

 been kept for a single species described by Norduiann, though the 

 generic differences of this from Lernanthropus are very doubtful. 

 Two new genera described by me in 1898 {Oybicola and Pseudo- 

 claveUa) have been added. 



The family Philichthyid.'© (p. 477) has been formed to include 

 all those parasites which are found only in the mucous canals and 

 sinuses of various fish, and are so constructed as to be able to 

 move freely in these spaces, the female having neither articulate 

 limbs nor strong organs of attachment ; the male is, however, of 

 a distinct and rather high crustacean type. The first form found 

 was the PMlicJithys xiplice, Stp. ; it was placed in the last-mentioned 

 family, though the female resembled much a Chondr acanthus. 

 Hesse was the first to discover the minute forms, which he divided 

 into two genera, Lepospliile and Colobomatus. Since then Richiardi 

 has described eight species of Philichthgs, but they differ so much 

 from the original that I have made for them a new genus, giving 

 to it bis name. Hesse, Eichiardi, and Carl Vogt were strongly 

 of opinion that these peculiar animals were worthy of being formed 

 into a family of their own, especially as the known males are 

 much alike and distinct. 



