MUSEUM OF COMPARATIVE ZOOLOGY. 119 



Thoa siphonata Pourt. 



Stem composed of irregularly twisted tubes; branches irregularly pin- 

 nate. Polyp-cells very small and scarce, tubular, at the base of the pedun- 

 cle of the very long, tubular ovarian cells. The latter are bent at right 

 angle near the top and terminate in a round aperture. Half an iuch high, 

 on Terebratula?. 



Off Havana in 270 fathoms. 



Tubularia crinis Pourt. 



Irregularly branching ; branches rather smaller than horsehair, of dark 

 horn-color, wrinkled at intervals; polyps terminal, large, not retractile. 

 About two inches high, attached to tubes of Annelids. Off Sand Key in 

 100 fathoms. 



In determining the Hydroid polyps, I have made use of the older generic 

 names. The newer subdivision of these genera being based chiefly on 

 characters derived from the softer parts, it is almost impossible to assign a 

 polyp to its proper place in them, unless observed alive. 



It would be premature to compare this deep-sea Fauna with the 

 animals inhabiting the regions of lesser depth on the coast of Cuba 

 or Florida. In the first place, many of the smaller forms of animals, 

 such for instance as the Bryozoa or the Hydroid polyps of those shores, 

 are not yet sufficiently known to enable us to say if any of the species 

 dredged exist in any other than the abyssal region. Then, a very dif- 

 ferent value must be assigned to the different classes of animals under 

 examination. Thus, the dead shells must be left out of the question, at 

 least the smaller ones, for they may have been dropped with the excre- 

 ments of fishes, or, in the case of Pteropods, have sunk from the surface 

 after the death of the animal. The Crustacea and Annelids being 

 abundant and generally sedentary will, when better known, afford good 

 characteristics of the regions of inequal depth, The same remark 

 applies to the Sponges and the Foraminifera ; the great abundance of 

 the latter and the ease with which they may be procured with the 

 sounding-lead renders them particularly useful. 



The Echinoderms appear to have a wide range in depth ; at least we 

 have two species (Cidaris annidosa and Tripncn.stes ventricosus) which 

 are common to the shore and to the depth of 27<» fathoms. The upper 

 and lower limits of Pentacrinus are not yet known. 



Of the corals, none of the species found in our dredgings are known 



