MEDUSA OF WOODS HOLE REGION. 



59 



SIPHONOPHORA. 



Almost, if not all. the members of this order likely to be taken in the VV Is Hole region arc im-i- 



ilental rather than internal faunal factors, home hither by tropical currents or prevailing winds from 

 seaward. The proximity of the Gulf Stream and its general course are undoubtedly the most domi- 

 nant influences in transporting various subtropical faunal elements to these waters. 



The following synopsis furnishes hardly more than a convenient check list of species of which I 

 have hern able to find records, and only a comparatively few of which I have personally taken during 

 the more than ten years of observation and collecting within the region. 



Tl der Siphonophora comprises three fairly distinct suborders or sections. 



DlSCONECT-K. 



With discoidal pneumatophore, hut devoid of nectophores or bracts. 



VELELLA Bosc (1802), 



Velella mutica Bosc. 



VeleUa mutica Bosc, His Wire Naturelle .lis Vers, Tome II. lsifi. p. 158. 1, Agassiz, Contributions Natural History United 



States, Vol. IV, 1862, p. 366. A. Agassiz, North American Acalephse, lst'.o, p. 216. 

 Armenista mutica Haeckel, Siphonophora Challenger Report, Zoology, Vol. XXVIII. ls>\ p. si 

 Velella mutica Mayer, Bulletin Museum Comparative Zoology, Vol. XXXVII, 1900, p. 71. 



Pneumatophore an elliptical or oblong disc, usually with an oblique vertical crest, and with 

 numerous zooids suspended from its lower surface. Color of radial canals and manubrium often bril- 

 liant ochraceous. Occasionally taken in Vineyard Sound, Buzzards Hay. and off Newport. 



PORPITA Lamarck (1816). 

 Porpita linnseana Lesson. 



Porpita linnseana Lesson, Histoire Naturelle des Zoophytes Acalephes, 1843, p. 589 

 I.. Agassiz, Contribution Natural History United States, Vol. IV. 1862, p 

 $66. A. Agassiz, North-American Acalephse, 1865, p. 218. Mayer. Bulletin 

 Museum Comparative Zoology, Vol. XXXVII, 190U. p. 72. 



Pneumatophore a circular disc hut devoid of vertical crest, other 

 wise similar in general aspects to the preceding. 



Distribution. — Occasionally taken at Woods Hole, Vineyard Sound, 

 Newport, R. I., etc. 



( 'alyconect.E. 



Without piieiiiiiatophores. hut with one or more nectophores. 

 DIPHYES Cuvier i 1817). 



Diphyes bipartita Costa. Text cut. 



LHphyt s bipartita Costa, < lenere Diphya, ism, p. 4. 



Diphyes acuminata Fewkes, Bulletin Museum Comparative Zoology, Vol. VI 1880, 

 P 142. 



Diphyesbipartita Chun, Siphonophoren der Kanarischen Inseln, 1888; Siphonophoren 

 der Plankton-Expedition, 1897, p. 24. Mayer, Bulletin Museum Com- 

 parative Zoology, Vol. XXXVII, 1900, p. 74. 



This species is widely distributed throughout the tropical Atlantic 

 anil not infrequently drifts into the bays of the region from the Gulf 

 Stream. Mayer records it as often taken at Newport in late sum- 

 mer. Specimens were taken off the borders of the Gulf Stream during 1902. Figure 25, after Mayer, 

 gives a good general impression of the shape of this medusa, hut no figure can give the remotest idea 

 of its delicacy or mi itions. 



Diphyi t bipartita. After Mayer. 



