ISfiG] DR. W. BAIRD ON A MONOECIOUS WORM. 101 



5. Description of a New Species of Monoecious Worm, be- 

 longing to the Class Turbellaria and Genus Serpentaria. 

 By W. Baird, M.D., F.L.S., &c. 



The Worm which I now bring before the notice of the Zoological 

 Society is in the collection of the Derby Museum (the Free Public 

 Museum) of Liverpool ; and I am indebted to the kindness of Mr. 

 Moore, the Curator of that institution, for an inspection of it. It 

 was presented to the Museum by Captain Berry, of the ship 

 ' Richard Cobden ' of Liverpool ; and I have given his name to the 

 species. 



Serpentaria berryi, nov. sp. 



Body flattened, ribbon-shaped, thicker and broader at the anterior 

 extremity, becoming thinner and narrower as it descends. The cen- 

 tral portion of the body is the thickest, becoming sharp at the outer 

 edges. The anterior part of the body is rather convex, and finely 

 striated across for a length of about 5 or 6 inches. After that, it is 

 smooth, but marked on the dorsal surface with a keel or raised nar- 

 row ridge, which runs down throughout the remainder of its length 

 to the posterior extremity. It is divided into very numerous narrow 

 segments. The mouth is very small and obscure. The fissures on 

 each side of the head are distinctly marked ; and the aperture under- 

 neath leading to the visceral cavity is large, oval, and strongly puck- 

 ered on its inner edge. As preserved in spirits, the colour appears 

 to be a uniform dull greyish yellow. - 



Total length of specimen, preserved in spirits, 16 inches; breadth 

 at about 2 inches from the anterior extremity 9 lines, breadth near 

 the tail about 3 lines. 



In general shape this Worm approaches very nearly to one found 

 on the northern shores of our own coast, the Serpentaria fragilis of 

 Goodsir, especially as that species is represented by Sir J. Dalyell in 

 his ' Powers of the Creator,' vol. ii. pi. 6. A large Worm from the 

 coast near Montrose has also been described by Dr. Gray in the 

 ' Proceedings of the Zoological Society ' for 1857, under the name of 

 Lineus beatticei, which in many respects resembles this species, 

 though perhaps that may be identical with the Serpentaria fragilis 

 of Goodsir. 



Captain Berry, in his notes upon the capture of this Worm, says, 

 " This Worm was taken in a drift-net off Singapore, and kept alive 

 in a bucket of water for a day or two. When at rest it lay at the 

 bottom, contracted to about 6 inches in length. When swimming, 

 it stretched to about the length it now is ( 1 6 inches) ; but when irri- 

 tated, it stretched to a length of between 2 and 3 feet. When put 

 into spirits, it vomited the other Worm in the bottle." 



One of the peculiarities of the family to which the genus Serpen- 

 taria belongs, is the curious facility which these Worms possess of 

 vomiting, or expelling from the large aperture under the head, the 

 whole of the alimentary canal. A case of this sort was recorded by 



