162 CLASS IV. 



* * Body armed posteriorly with zones of horny setae. Echiurus 

 Cuv. (Echinurus). 



Sp. Thalasscma eckiurus, Lumbricus eckiurus PALL., Misc. Zool. x. Tab. i, 

 fig. r 5, FORBES, Brit. Starf. p. 263, GUER. Iconogr. Zooph. PL 6, fig. 3 ; 

 on the coasts of the North Sea ; this species is used by the fishermen for 

 bait ; it is flesh-coloured, here and there translucent blue and red ; the 

 spines are shining and yellow, as far as they project from the body. The 

 orange- coloured intestinal canal is long, with many undulations and 

 vesicular expansions. There are two long, brown, somewhat tortuous, 

 caecal tubes near the anus, and four white vesicles at the anterior part 

 of the body, which belong to the procreative apparatus. The nervous 

 system consists of a thread running along the intestinal cavity. The skin 

 has much muscularity, so that when wounded it spirts out the contained 

 water like a fountain, and then the intestines are forced out. 



*** Body furnished anteriorly and posteriorly with zones of 

 setae ; with belly in the middle plane and in front of the anus 

 scutate. (Setae at the sides of the scute ; anal tubule conical, 

 retractile.) Sternaspis OTTO. 



Sp. Thalassema scutatus RANZANI, Sternaspis thalassemoides OTTO, Nov. 

 Act. Acad. Leop. Carol. Tom. x. Tab. 50, GUERIN Iconogr. Zooph. PI. 6, 

 fig. 4, from the Adriatic. OTTO took the conical extremity incorrectly for 

 the mouth ; see the communication relative to the structure of this animal 

 by KROHN in MUELLER'S Archiv. 1842, s. 426. RANZANI, who described it 

 before OTTO, rightly distinguished the two extremities of the body, and also 

 figured the spoon-shaped proboscis, in which it resembles Echiurus. Opuscoli 

 scientifice I. Bologna, 1817, 4to. pp. 112 116, Tab. iv. f. 10, u. 



