130 LEOCRATES ATLANTICA. 



the latter and Dr. Johnston's species. The name (Psamathe) given by Dr. Johnston had 

 already, in 1814, been nsed for a Crustacean by Rafinesque, and in any case lapses in 

 favour of the earlier title of Savigny. There is no reason why the Psamathe cirrata of 

 Keferstein should be separated. Fine examples under the latter title (Kefersteinia cirrata) 

 were sent from Plymouth by Dr. Allen. 



Dr. Williams (1851) mentions that it feeds on algse, but this is doubtful. Dalyell 

 found that it fed voraciously on mussels, " darting out its proboscis and absorbing a great 

 quantity. The colour changes with the quality of its food." 



Genus XLI. — Leoceates, 1 Kinberg, 1865. 



Head with three tentacles, a pair of palpi, and a frontal tubercle ; eyes four. Body 

 comparatively short, with few segments, ending in two anal cirri. Proboscis with two 

 maxillas. Foot biramous; dorsal bristles capillary; inferior bristles compound (falcate). 



This genus was established by Kinbergin 1865 for a species from China — near Hong 

 Kong. The author gives the proboscis only a single "maxilla" in the median dorsal 

 aspect, but probably the second was overlooked. 



Claparede again constituted the genus Tyrrhena, as indicated, for the same type 

 which Achilla Costa had discriminated under the name of Castalia Glajparedii in the 

 manuscript of the fourth ' Annuaire du Musee Zoologique de Naples. 5 



Gi-rube 2 showed the identity of the genera established by the two preceding authors, 

 and gave an amended description of the genus in his Philippine Annelids, with an account 

 of a new species from Zamboanga. 



1. Leoceates atlantica, Roule, 1896. Plate LVIII, fig. 17— head; Plate LXIX, fig. 

 17— foot; Plate LXXVIII, figs. 5 and 5 a— bristles. 



Specific Characters. — Head (in spirit) more or less quadrate, longer diameter antero- 

 posterior, and generally with a median depression and a cordate posterior border. Eyes 

 on an elevated ridge in middle of head ; anterior pair wide apart, large, rounded, and with 

 a cuticular lens ; posterior pair also rounded or oblique. Palpi thick at the base with 

 a short terminal segment. Lateral tentacles subulate and slender; internal to palpi. 

 Median tentacle short and subulate. Tentacular cirri eight, with massive basal segment 

 (ceratophore) and spine. Body about one and a half inches long, massive anteriorly, 

 though tapering a little towards the head in life and more distinctly posteriorly. Rounded 

 or convex dorsally, iridescent and minutely ringed, flattened ventrally, and with a deep 

 median groove. First four segments fused, but with special nerve-twigs. Proboscis with 

 a thick, frilled, anterior edge, a blunt papilla projecting from the central fold dorsally. 



1 ' Ofvers. af K. Vet.-Akad. Fork/ 1865, No. 4, p. 244. Claparede, in 1868, constituted the 

 genus Tyrrhena for the same form, naming it after the Tyrrhene Sea opposite Tuscany. ' Annel. 

 Neap./ p. 227. 



2 ' Jahresb. Schles. Gesellsch./ November 19th, 1879, s.a., p. 25; 'Anneliden fauna der 

 Philippinen/ p. 105 (1878). 



