gland in the adult, but dilating as it approaches the calyx, which, like the distal part of the 

 stalk, is marked by transversely running grooves, giving a crenulated appearance to the profile 

 of these parts. Stomach vvith some indication of lateral lobes. Buds as many as four at a time 

 (two on each side). Tentacles numerous, at least 20 in number. Sexes apparently separate. 



The specimens to which this description refers do not form part of the 'Siboga' Collection, 

 but were found at Singapore and Pulu Java, Malacca, by Mr W. F. Lanchester, after whom 

 I have the pleasure of naming the species, on the tails of two specimens of a Sipunculid, 

 determined by him as Phascolosoma pellucidum var. They were presented to the University 

 Museum of Zoology at Cambridge, but the type-specimen will be transferred to the British 

 Museum, while a duplicate will be placed with the 'Siboga' Collection. 



The material is unfortunately badly preserved, and some of it was further injured by the 

 use of oil of cloves, which produced great contraction. The specimens transferred from absolute 

 alcohol directly to Canada balsam dissolved in the same fluid l ) are much more satisfactory. 



The measurements of the largest specimen found (fig. 4) are as follows : — length of 

 calyx, 346 'j.\ breadth of calyx, at its widest part, 308 fi; length of stalk, 896 y.\ breadth of 

 stalk, at the proximal end, 58 y. ; breadth of the stalk, just before it joins the calyx, 134 u.. 

 The other specimens are smaller-, the smallest having the measurements (given in the same 

 order) 180, 166, 300, 51 and yj; two other individuals being intermediate in these measurements 

 between the largest and the smallest specimens. It will be seen that the individuals of the 

 present species may be described as very large ; and this is sufficiently brought out by comparing 

 the figures given with those of other species 2 ). 



The number of tentacles cannot be given with certainty; but it is at least 20, and is 

 probably more. The alimentary canal is not well shown, but the intestine, rectum and some 

 indication of the stomach may be seen in fig. 4. The specimen here represented appears to be 

 a male; a pair of organs which are almost certainly testes being - visible in the figure. The buds 

 are only visible in one of the slides which is not successfully mounted; but, in one individual, 

 four buds are present; — a large one on each side (the two not differing much in size) and 

 a small one at the base of each of the larger ones. The buds are not well enough preserved 

 to decide the question whether a food-gland is present or not. 



It can hardly be doubted that the present species is different from other species which 

 have hitherto been described from the tails of Sipunculids [L. fihascolosomatum Vogt, 1876; 

 L. murmanicum Nilus, 1909; L. brumpti Nilus, 1909; L. minutum Osburn, 1910; and L. 

 sluitcri, described below). It has some resemblance to L. antedonis, described by Mortensen 

 (191 1) from the cirri of Hathrometra (Antedon) prolixa Sladen, from Greenland. 



2. Loxosoma sluiten' n. sp. (PI. I, fig. 7). 



373. A. On Phascolion convestitus Sluiter. Stat. 105. 6° 8' N., i2i°i9'E., 275 Metres; coral-bottom. 

 Calyx about 150 u. in length, and about 85 a in breadth, without cirri or lateral 



1) For the use and advantages of this method, see my paper in Quart. J. .Mier. Sci., XI. VI, Pt 2, 1902, p. 264. 



2) The figures were all drawn to the same scale ; but it must be noted that while those on PI. I were only reduced 2 / 3 , those 

 on PI. II are reduced '/ 2 . 



S1BOGA-EXPEDITIE XXVIII O. 



