and on two new Species of Echinodermata. 75 



latiores ; brachiorum syzygiis plerumque 4-articulatis ; pin- 

 nulis sub 40, quarum intimse 45 filiformes sequentibus 

 multo longiores." 



Family Sipunculidse. 

 Phascolosoma radiata, n. sp. 



Body vermiform, cylindrical, tapering a little posteriorly, and 

 terminating in a conical button, which is longitudinally furrowed. 

 The anterior part of the body is subconical and a little flattened 

 above, where it is marked with radiating furrows, above and 

 below which it is coarsely granulated, the granules becoming 

 finer on the remaining part of the body. The proboscis is very 

 long, delicately ringed or transversely striated, and terminating 

 in a smooth aperture without tentacular filaments. The upper 

 portion of the proboscis is transparent and flesh-coloured ; the 

 lower more opake and yellowish. The body is yellowish, 

 spotted and streaked with dark brown on the more prominent 

 parts. Length of body 2 inches ; proboscis nearly the same. 



Mr. Barlee got a single specimen of this fine species from 

 deep water, which he kindly sent me alive. It occupied a 

 broken shell of Aporrhais pes-pelecani, from which the fore part 

 of the body protruded considerably. It threw out its proboscis 

 to a great length in search of food, generally holding it in a 

 curved or spiral position. 



The genus Phascolosoma was constituted by Leuckart, in his 

 ' Breves Animalium Descriptiones, &c./ and appears to differ 

 from Sipunculus principally in the absence of the circle of feelers 

 round the mouth ; but the genera of the Sipunculidte are very 

 badly defined, and will require revision when the species are 

 better known. At present very few of them are described. 



The Phascolosoma longicolle of Ruppell, found inhabiting 

 corals in the Red Sea, has considerable resemblance to our 

 species, but is evidently distinct. 



EXPLANATION OF PLATE V. 



Fig. 1. Campanulariafastigiata, highly magnified. 



Fig. 2. One of the dorsal cirri of Comatula Sarsii, magnified. 



Fig. 3. Do. do. Comatula rosacea, magnified. 



Fig. 4. Phascolosoma radiata, with the proboscis extended (the line shows 

 the natural size). 



Fig. 5. The same, with the proboscis retracted. 



Fig. 6. The same, with the shell partially broken away, to show the pos- 

 terior extremity. 



