182 Dr. E. L. Trouessart — Synoptical Revision 



loped ungueal groove. Dermal plates pitted only on the back. 

 Total length 0-60-0-65 millim. 



Hab. French coast : Pas de Calais, at Wimereux (Giard), 

 upon Eudendrium capillare; Le Croisic (Chevreu.c), upon 

 Bryozoa [Alcyonidium hirsutum), and Baie de Port-lin upon 

 Facus serraius. Baltic : Kiel (Lohmann), region of Red 

 Alga?, at 12 fathoms. 



6. Halacarus striates. 



Lohmann ( 8), p. 74. fig. 117. 



H. menus, Trouessart (7), p. 7-54. 



Char. Anus terminal. Xo spine on the third joint of the 

 p>alpi. Ocular plates narrow, without cornea. Dermal plates 

 pitted only on the back. Claws pectinate. Xo ungueal 

 groove on the tarsi. Total length 0'62-0-70 millim. 



Hab. French coasts: Le Croisic (Chevreux), Laminarian 

 zone, upon Corallines ; Baie de Port-lin and open coast upon 

 " inalis. North Sea, upon Thuiaria Thuia, off 

 Xewcastle-on-Tyne (Giard). Baltic: Kiel (Lohmann), re- 

 gion of Bed Alga?, at 3-5 fathoms. 



Subgroup 2. — Abdomen short, with a semicircular outline 

 posteriorly ; flanks swelled, convex, and not parallel. 



7. Halacarus spinifer. 



H. ctenopus, pt.. Trouessart (7), p. 754. 



H. globosus, Trouessart. MS., toe. cit. 



H. spinifer. Lohmann (8), p. 75, figs. 101, 102. 



Char. Palpi with the third joint furnished with a strong 

 spine on its inner margin ; third joint of first pair of legs 

 armed with two spines behind the triangle formed by the 

 dorsal seta?. Claws of the first pair very short and very 

 stout; all the claws pectinate. Ocular plates with cornea?. 

 Epistomial plate produced into a point above the rostrum. 

 Anus terminal. 



The adults are generally of a dark colour (brown, more or 

 less blackish) ; the young and the nymphs are light-coloured, 

 yellowish, or of a more or less lively coral-red. It is the 

 largest species known in the family, and one of the commonest 

 on our shores. Total length l-00-l'lO millim. 



Hab. French coasts: Pas de Calais, Wimereux (Giard), 

 upon the byssus of mussels, on Lasaa rubra and Eudendrium 

 capnllare ; canal from Caen to the sea (Le Sentchal) in brackish 

 water, on Hydroids ; Atlantic coast; Le Croisic [Chev- 



