AMERICAN IIYDROIDS. 



Nematophores of the Statoph-a. In the Statoplea the nematophores are always fixed and 

 almost always monothalamic, the only exception known to me being in the "minuta" group of 

 Aglaophenia (fig. 51) and in Nudithn-n dalli (fig. 72), where the nematophores, especially the 

 mesial ones, exhibit internal ridges fully as pronounced as in many typical Elentheroplea. 



There is more diversity in the nematophores of the Statoplea than in the other group, and 

 their size is, oil the average, considerably greater; so much so that it was found inexpedient to 

 represent them all on the same scale in the accompanying figures, where figs. 60, 61, and 74 are 

 much less magnified than the others, the remainder being represented on the scale adopted for the 



TYPICAL M M\ l 'MI-HI ntEs UK Till-; sTATopLKv. M ueli enlarged. 



Fig. 51. .lijlaniilienin iiiiniita. a, extensible prcjei'ss of saivu- 

 style ; Im, liydrutheral aperture ; 71, uematoeysts; sa. 

 superior lateral aperture; ra, termiljal aperturv of 

 neiuatupliore. 



Fig. 52. A. miiiuta, supraoalycine. 



Fig. 53. .1. lophocarpti, mrsial. 



Fi<, r . 54. .1. loplivcart'fi, supraealyctno. 



FIL'. ."ij. J. bicornuta. mesial. 



V\'j. .~ii;. A. rhynchocarpa, a,eaiiline ; E>, conical process. 



Fi^. 57. ^1. cristir'n'iiif. eauline. 



Fig. 58. A. inainiiiillata, cauliue. 



Fig. 59. .1 aj>erta, eauliue. 



Fig. 00. Cladocarpvit parailix''", sii] racal_\ cine. 



Fi}.'. 61. <'lailiicarpusparadisea,nn'8ia\. 



Fiy. 62. C. carinalvs, supracalycine. 



Fij:. (j:j. C. caiinatus, mesial. 



eleutheropleau nematophores. The typical arrangement among the Statoplea is represented in 

 A. lopliwtirjia (lig. 53), in which the supracalycine pair are small, monothalainic, slightly geniculate, 

 even rimmed, and the mesial nematophore is rather short and spin-like, with a terminal aperture 

 and a perforation between the actuate portion and the hydrotheca. In most species of Cladocar- 

 pus (fig. CO) the supracalyciue nematophores are very broad above and constricted below. In 

 others of the same genus their margins are distinctly denticulate, a condition of affairs quite 

 characteristic of the genas Aglaophenopsis. In Cliidoi-arpus carinatus (rig. Gl') these structures 

 arc constricted at the distal end and have an aperture much smaller than the greatest internal 



