4 BOTRYLLlDiE. 



Oeiiiis DIDi:iTI]\HJilI, Savigxy. 1827. 



Test coriaceous, polymorphous, sessile, and incrustiiig ; systems 

 numerous, compressed, without central cavities or distinct circum- 

 scription. Individuals scattered ; abdomen pedunculate. Ovary 

 placed l)y the side of the intestinal loop, increasing in length wlicn 

 the eggs are fully developed. 



The Tunicaries composing the systems of individuals in this genus 

 are without any apprecial)le order of arrangement, and are scattered 

 over the common body. 



Didemniuni roseum. 



Didemniam roseum, Savignv, &c., Saks, Reise i Lofoten eg Fiiimarken, p. 33, 1850. — 

 Packard, Inv. of Labr. in Mem. Bost. Soc. N. H. i. 27.'j (1867). 



Colony forming a calcareous, thin, incrusting mass, coriaceous, 

 much expanded, surface finely granulated, licing covered densely 

 with round mammillated bodies. Branchial orifices rudely arranged 

 in quincunces, slightly raised above the surface, formed of six trian- 

 gular lol)es, with the alternating loljes a little unequal in size, com- 

 posed of three or four granules a little larger than those on the sur- 

 face generally. 



It bears a close resem])lance to Dldemninm exaratnm, Gi'ube 

 (Ausflug nach Trieste, Taf. ii. Fig, 2, 2 a), but the branchial o])en- 

 ino's are thicker, and the mass thinner and more calcareous in our 

 species. It agrees exactly with Sars's descri])tion of D. roseum, 

 though it is whitish in alcoholic specimens. 



Found frequently incrusting fucoids in masses an inch in diam- 

 eter, in ten fathoms, Hopedale ; and on the whole coast. I have 

 al?o dredged it at Eastport in twenty fathoms. (^Packard.) 



I can add no further information in regard to this species than 

 that contained in Dr. Packard's description copied above. 



Family SALPID^. 



Animal free, pelagian, in the form of a more or less cylindrical 

 tube open at one or both ends ; test and mantle continuous with 

 one another at the respiratory apertures, l)ut elsewhere separated 

 by a wide space ; gill forming a hollow band crossing the respira- 



