ECHINODERMATA. 161 



FORBES gives the name of Syrinx to the species which have a short 

 proboscis with an indented tentacular fold around the mouth, like Sipunc. 

 nudus. In other species the proboscis is longer, and there is a ring of 

 simple lancet-shaped tentacles round the mouth. Of these he forms his 

 genus Sipunculus, which appears to agree with Phascolosoma LEUCK. 

 Sp. Phascolosoma granulatum LEUCK. 1. 1. fig. 5, from the Mediterranean, 

 probably not different from Ascosoma Blumenbachii, ibid. fig. 5 ; Sipunculus 

 capitatus RATHKE, Nov. Act. Acad. Leop. Car. xx. i, Tab. vi. fig. 20, 21; 

 Sip. Bemhardus FORB. Brit. Starf. p. 251 ; it lives, like the Hermit Crab, 

 in the empty shells of Molluscs (Strombus pes pekcani, Littorina, Turritella, 

 Dentalium, &c.) 



Priapulus LAM. Body cylindrical truncated posteriorly. Pro- 

 boscis retractile ; no tentacles around the mouth. A branched 

 pyramidal appendage hanging from the posterior part. 



Sp. Priapulus caudatus, Holothuria priapus L., Zool. danica, Tab. xcvi. 

 fig. i, and cxxxv. fig. 2, FORBES Brit. Starf. p. 256. GUERIN Iconogr. 

 Zooph. PI. 5, fig. i. It is supposed that the bundle of threads at the 

 extremity of the body serves for respiration. This singular animal lives in 

 the North Sea. 



Bonellia ROLANDO. Body oval, contractile, with a long pro- 

 tensile proboscis, divided at the extremity into two lacinige. Anus 

 posterior, terminal. 



See ROLANDO in Journ. de Physique, de Chim., d'Hist. not. &c. Tom. 

 xcv. Juillet, 1822, pp. 49, 59, av. fig. (from the Mem. de I'Acad. de Turin, 

 Tom. xxvi. pp. 357, &c., Tab. xiv. xv.) The long proboscis was taken for 

 a tail by this writer, the anus described as mouth ; near the anus two 

 trussed organs are situated (salivary organs according to ROLANDO), which 

 correspond to the arborescent respiratory organs of HolotTiurice. The 

 intestinal canal is narrow and long, with two loops and many undulations. 

 Sp. Bonellia viridis 1. 1. fig. i, GUERIN Iconogr. Zooph. PI. 6, fig. i ; Bon. 

 fuliginosa. These two species were found by ROLANDO on the shore of 

 Sardinia. 



Tlialassema Cuv. Body cylindrical contractile. Proboscis short, 

 with spoon-shaped appendage, or sulcated lacinia, undivided. Two 

 shining uncinate setae in the anterior part of the body, behind the 

 proboscis. 



* Body smooth posteriorly. Thalassema GAERTNER. 



Sp. Thalassema Neptuni GAERTN., PALL., Spicil. Zool. x. Tab. i. f. 6, .GUE~RIN 

 Iconogr. Zooph. PI. 6, fig. i, FORBES Brit. Starf. p. 259. (Here also seems 

 to belong the genus Ochetostoma LEUCK., Sp. Ochet. erythrogrammon, Atlas 

 zu der Reise VON ED. RUPPELL, Neue wirbellose Thiere des rothen Meeres, 

 1828, Tab. n. fig. 3, Holoth. eaouari LESS. Cent. Zool. and GUER. Iconogr. 

 Zooph. PI. 4, fig. 6. 



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