440 MR. 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. Tlie young unattached forms of 

 this species have been taken in the tow-net jjy 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 PenelJa. 



In the family Ergasilidae (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 acideatus, from which, too, a species of the latter genus 

 is taken ; I have therefore united them together. 



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

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

 known by many names ; these I have eudea^■oured to place in their 

 proper places. The genus Papulina of Van Beueden has been 

 relegated to Lepeophilieirus, 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 Lepeophilieirus huttoni of Thomson, taken 

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

 send me, should be placed with Gloiopotes 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- 

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

 use, and Van Benedeu's Chlamys is of more recent origin. 



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

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

 generic differences of this from Lernanthropus are very doubtful. 

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

 clavella) have been added. 



The family PhilichthyidiB (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 Philichthys xiphce, Stp. ; it was placed in the last-mentioned 

 family, though the female resembled much a Chondracanthus. 

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

 into two genera, LeposphUe and Colobomntus. Since then Eichiardi 

 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 liis name. Hesse, Kichiardi, and Carl Yogt 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. 



