MUSEUM OF COMPARATIVE ZOOLOGY. 249 



widening towards the oblique orifice ; the outer portion of the margin cut into 

 five rather shallow teeth, intrathecal ridge strong and continuous with one 

 across the stem of the branch. Nematophores are found in connection with 

 the hydrothecoc, and upon the stems ; supra-calycine nematophores very large 

 and prominent, stretching far beyond the edges of the hydrotheca), orifice ter- 

 minal and continued laterally on the inner side towards the pinna ; mesial 

 nematophore large and strong, extending above the edge of the hydrotheca, 

 adna'te througliout, orifice like those of the supra-calycine nematophores ; cuu- 

 line nematophores quite variable in form, two on each internode, more or less 

 triangular, with rounded or with one of the upper corners greatly produced, 

 tapering towards the base ; external orifice very large, extending entirely across 

 the upper margin and into the lateral processes, when the latter exist ; the 

 opening from the cavity of the nematophore into the stem is also very large, 

 often being equal in size to the internal orifice of the hydrotheca). At the base 

 of each pinna, in a direct line with the hydrothecaj, is an oval swollen process, 

 with a small circular orifice on the upper surface near the j^roximal end ; its 

 cavity is directly continuous with that of the hydrotheca iu front of it, and 

 also with that of the stem. 



Gonosome. — Unknown. 



Localities. — Ten miles north of Zoblos Island. Lat. 24° 8' N., Long. 82° 

 51' W. Depth, 339 fathoms. 



The most prominent feature of this interesting species is the great develop- 

 ment of the nematophores. Those in connection with the hydrotheca; are 

 above the average size, and those of the stems are among the largest known ; 

 the peculiar processes borne on the bases of the pinnae may also perform the 

 functions of nematophores, but until live specimens have been examined it 

 will be impossiljle to say. Of the two cauline nematophores found upon each 

 internode the proximal one has always the more regular outline, owing prob- 

 ably to the fact that on this portion of the intemodes there is an abundance 

 of room for them to develop in every direction, while those situated on 

 the distal end are limited in their growth in one direction by the basal pro- 

 cesses of the pinna\ This will readily be seen by reference to the figure. It 

 is also worthy of notice that the corner of the distal cauline nematopliore 

 W'hich is most strongly produced is the one on the opposite side to the base of 

 the pinna. By stretching out in this direction it reaches a freer space in which 

 to manipulate the protoplasmic processes which it may send forth. 



The cocnosarc of the most proximal hydrotheca on each pinna finds its way 

 to the cocnosarc of the main stem by passing directly through the cavity of the 

 oval basal process, and from the size of the opening of the basal process I im- 

 agine that it must be used for the protrusion of protoplasmic processes like 

 those from an ordinary nematophore. The process diff'ers, however, from the 

 ordinary nematophores in containing a portion of true cocnosarc, and to this 

 extent it approaches the nature of a hydrotheca ; that is, there exists a swollen, 

 oval process of the perisarc, containing a process of the cocnosarc, and with 

 (what in all probability is) a mesial nematophore upon its upper surface. It 



