(I) Loxosoma Keferstein : Genotype L. singulare Keferstein. 



The foot is a sucking disc, provided with straight and oblique muscles. No foot- 

 gland, even in the buds. 



(II) Loxocalyx Mort. (nov.) : Genotype L. raja Schmidt. 



Foot-gland present in the adult, as well as in the buds; the foot usually with 

 wing-like expansions. Only straight muscles are developed in the foot. 



(III) Loxosomclla Mort. (nov.): Genotype L. crassicauda Salensky. 



Foot-gland present in the buds, but not in the adults. Only straight muscles are 

 present in the foot. 



The persistence of the foot-gland in the adult is a feature which marks off a certain 

 number of the species from the rest ; and perhaps entitles them to genene rank. I feel less 

 convinced that the other species are sufhciently well known to warrant the separation of 

 Loxosomella from Loxosoma. 



Loxocalyx Mortensen. 

 191 1, t. cit., p. 406. 



The 'Siboga' collection contains two species which are referable to this genus. The state 

 of preservation of the first of these is not good enough to allow several important points to 

 be made out. I am unable, for instance, to state definitely what is the number of the tentacles; 

 but on the whole I think I am justified in describing it as a new species. 



I therefore record it under the name of 



1. Loxocalyx lineatus n. sp. (PI. II, figs. 1 — 3). 



332. C, on a Siliceous Sponge [Halichondria sp. ')). Stat. 64. Kambaragi Bay, Tanah Djampeah, 

 o — 32 Metres; coral, coral-sand. 



Calyx from 220 to 320 u. long, 190 — 230 y. broad; with moderately developed lateral 

 membranous expansions. Number of tentacles uncertain, perhaps 10. A series of vesicular cells 

 encircles the distal part of the lophophore. Buds not numerous. Stomach with well developed 

 lateral lobes. Stalk from 570 to 670 y. long, usually about twice the length of the calyx ; 

 marked by four longitudinal lines (the nature of which is uncertain), to which the specific name 

 refers. Foot with well marked alate expansions and a persistent foot-gland. 



The specimens were found on the outside of a species of Halichondria, of narrow 

 cylindrical form. 



Several Polychaets belonging to the family Syllidae occurred in the interior of the 

 cylindrical branches of the Sponge. 



The examples selected for figuring bear only one bud each, represented merely by a 

 subspherical swelling. In other individuals the bud of one side had nearly reached its limit of 



1) I am indebted to Mr R. KlRKI'ATRlCK for tliis determination. 



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