ANTHOZOA OP THE WOODS HOLE REGION. 235 



SAGARTIID.S Gosse, 1858. 



Body with strong oral sphincter and numerous highly contractile tentacles. Mesenteries of two 

 sorts; principal series in six pairs attached to cesophagus, and devoid of gonads; second series incom- 

 plete, and bearing gonads in breeding season. Acontia present and protrusible through cinclides or 

 directly through the tissues. 



BOLOCERID.E McMurrich, 1893. 



Sphincter more or less diffuse and weak; mesenteries devoid of acontia; pedal disk well devel- 

 oped; tentacles stout, nonre tractile, strongly constricted at base, hence often deciduous. 



BUNODID.B Gosse, 1858. 



Sphincter entodermal, "body usually studded with numerous tubercles, which are disposed in 

 longitudinal rows, and may serve as suckers by means of which they have the faculty of adhering with 

 force to foreign bodies. " (Gosse.) Mesenteries often numerous and perfect but devoid of acontia. 



PARACTID^ Hertwig, 1882. 



Sphincter mesogleal, strong; body usually devoid of tuberculation, but with numerous longitudinal 

 flutings; mesenteries numerous and perfect ; no acontia. 



TEALirO^ Hertwig, 1882. 



"Hexactinia with numerous perfect mesenteries; sphincter strong, entodermal. projecting as a 

 thick swelling into gastric cavity. " 



"The most important feature of the family is, I consider, the extremely characteristic circular 

 muscle, which can be recognized with the naked eye, as a thick swelling on the inner side of the wall. 

 In transverse section it shows a circular or oval figure, fastened on one side to the wall; it is formed by 

 the extremely strong pleating of the entodermal circular muscle layer. The large number of perfect 

 septa is also important; on the other hand, I have entirely disregarded the nature of the surface of the 

 body, so that forms both with smooth and warty wall may find their place in the family." (Hertwig, 

 op. cit., p. 25-) 



Diagnostic Synopsis of Families of Hexactinia (modified from Hertwig)." 



A. Tentacles forming simple wreath. 



a. Digitate. 



b. Pedal disk absent. 



„. , , , , ,. , f Without conchula Ilyanthid.B. 



c. Siphonoglyphs and sphincter obscure-!,,,.,, , , _ 



'^ ° -^ '^ '^ iWith conchula SiPHONACTiNiOiB. 



66. Pedal disk present. 



, , ,. ^ ._• ^ J , ,. ,  f Absent .. Sagartiid.«. 



a. Acontia present, sphincter mesodermal, cuticular covering^ ,, _ 



•^ '^ ''(Present . . Puelliid<b. 



Absent Antheomorphud.®. 



[Weak ACTINIID.B. 



dd. Acontia absent, sphincter^ g^^^^^g entodermal Bunodid^. 



Present' Strong mesodermal Par.\ctid.(E. 



Mesodermal, transverse axis 



elongated Amphianthid<B. 



aa. Tentacles abnormal in shape. 



e. Clavate, knobbed HETERACTroa. 



ee. Replaced by stomidia LiponEmiD/B. 



eee. Branching or bushy f SarcophianThid;8. 



IThALASSIANTHID/B. 



B. Tentacles form double or multiple wTeaths CorallimorphiD/B. 



«Cf. Challenger Report, vol. xxvl, pt. 73, p. 7. 



