140 BULLETIN OF THE 



find no mention of it from New England waters. According to Agas- 

 siz, our Velella is Velella mutica of Bosc. Of that identification there 

 seems no doubt, considering where the animal which Bosc described was 

 found; but, as Pagenstecher * and Delle Chiaje suggest, it is difficult to 

 see exactly what Bosc meant by his other species, tentaculata. The for- 

 mer of these authors says Bosc called the Velella of Linne and Lamarck 

 mutica, while the species spirans of Forskal received the name tentacu- 

 lata, Mr. Alex. Agassiz mentions a V. septentrionalis from our Pacific 

 coast. Some of the material for the earliest descriptions of the Siphono- 

 phorse and Velellidae was collected in the Pacific Ocean, and near our 

 western shores, and we should naturally expect these species taken by 

 early voyagers from those localities. 



Porpita I have never seen alive in our waters, but have a dried speci- 

 men preserved on paper after the manner of a plant, taken by a sailor 

 not far from Nantucket. Prof. McCrady describes a species of Por- 

 pita from Charleston Harbor, not very different from Guilding's Porpita 

 {Polyhrachionia Linneand), which he calls Porpita Linneana, He is 

 inclined to think it a new species. 



The only known member of the long-stemmed Siphonophorse, provided 

 at one end with a float or air-bladder, which has been described from 

 New England waters, is Agalmopsis cara {Nanomia cava, A. Ag. ; Ste- 

 phaiiomia cara, Metsch. ; Halistemma carum, Haeckel, Glaus, Packard, 

 and others). This animal was first described by Mr. Alex. Agassiz, 

 to whom we owe so much of our knowledge of the Jelly-fishes of our 

 waters. The drawings and descriptions of the development which he 

 gives are not only the earliest of this particular genus, but, with those of 

 Glaus, Leuckart, Kolliker, and Gegenbaur, of the embryology of the 

 Siphonophorae as a whole. 



As I have already said, Haeckel considers Nanomia cara a species of 

 Halistemma, and places it under this genus in his table of the Agalmidse. 

 He seems to have been followed by Glaus, who adopts the name H. carum 

 in his Grundzuge der Zoologie. When Mr. Agassiz described the form he 

 said it was closely related to Agalmopsis as well as Halistemma, but that 

 the mode of arrangement of the swimming-bells and the nature of the 

 tentacles of the feeding polyps show undoubtedly that it cannot be placed 

 in the same genus as Agalmopsis, having in mind Sars's genus. NanomiOj 

 cara, according to Metschnikoff, as already shown, should be regarded 

 as a species in the genus Stephanomia. The reason for his conclusion, 

 he says, is on account of the resemblance between the larvae as figured 



* Pagenstecher, Zeitsch. f. Wiss. Zool., Bd. XII., 1863. 



