1905.] FROM SINGArORE AND MALACCA. 27 



I. Genus SiPUNCULUS. 



1. SiPUNCULUS ROBUSTUS Keferstein. 



E. Selenka, Die Sipunculiden (Semper's Reisen, iv. p. 97). 



Log. Singapore. Teluk Ayer ; two specimens. Pasir Panjang ; 

 two specimens. 



The longitudinal muscles do not anastomose at all, and number 

 26-27, both in front and behind, in three dissected specimens. 

 The ventral retractors arise in one instance from muscle-bands 

 1-5 on both sides, and in another instance from muscle-bands 2-5 

 on the right side, 2-6 on the left side ; in all cases the outer 

 oi'igins are small, about half the size of the inner. 



Colour in spirit, ash. 



2. SiPUNCULUs CUMANENSIS Keferstein. 



Selenka, toin. cit. p. 104. 



Zoc. Singapore. Pasir Panjang ; several specimens of var. 

 opacus, and three of var. vitreios. 



In the specimens dissected I find the nerve-cord thickening 

 ■ anteriorly, the thickening beginning at the level of the ventral 

 retractors, whence the cord gradually expands into a dorso-ventrally 

 flattened band running up the introvert. 



Among the specimens referred to var. opacus are several in 

 which the hinder portion (or half) of the body presents the trans- 

 parent colourless appearance of var. vitreus. In fully extended 

 individuals a greater or less portion immediately behind the ten- 

 tacles is also colourless or whitish. 



The specimens all have 20 longitudinal muscle-bands, except 

 one example of var. vitreus which has 26. 



3. SiPUNCULUS BOHOLENSis Semper. 



Selenka, torn. cit. p. 109. 



E coll. Hanitsch. Four specimens of this large species. 



Zoc. Gaya Island, British North Borneo. 



Ifab. Sandy shore, low water. 



In the specimen dissected the longitudinal muscles number 31 

 or 33 in the front and mid-regions of the body, and only 30 in 

 the hind part. The dorsal retractors arise each from four muscle- 

 bands, the ventral from, on the left side two, and on the right 

 side three bands. 



II. Genus Phascolosoma. 



4. Phascolosoma vulgare de Blainville. 



Selenka, torn. cit. p. 20. 



Loc. Singapore. Raffles Lighthouse, ooze under stones 

 seven specimens. Pasir Panjang, muddy sand ; one specimen. 



The only difiei'ence I can discover between these individuals and 

 Selenka's desciiption of Ph. vulgare is that the ventral retractors 

 arise at the anterior border of the posterior half of the body, 



