h must be recognized, further, as indicating the importance of the botrucnidae as a 

 classificatory factor, that th<-ir distribution differs markedly from that of the acontia. While, so 

 t'ar as is known, acontia occur only on the second and fourth protocnemes and on the second 

 deuterocnemes, and, furthermore, only on two ol these mesenteries at the most, i. <•. on either 

 the second and fourth protocnemes or on the fourth protocnemes and the second deuterocnemes 

 the distribution of the botrucnidse is much more extensive. Ihus in Cerianthula 

 i and Calpanthula guineensis they occur on th<- second, third and fourth proto- 

 cnemes; in Hensenanthula spinifer and //. melo on th<- same three protocnemes and on a 

 .:n number of deuterocnemes as well, the first in the one case and the first, second and 

 third in the other; and in //. <lactylifera they occur on the third protocneme and on the lirst 

 ;d and third deuterocnemes 1 ). Finally in Botryantkus benedeni they are stated t<> occur 

 on all th<- brachycnemic mesenteries and to be limited to these. The mosl striking feature of 

 this distribution is the occurrence of botrucnidse on the third protocneme in all the larval forms 

 and on brachycnemic mesenteries in both larval forms and Botryanthus, mesenteries upon which 

 acontia have never yet heen observed. 



In view of these facts, and until a fuller knowledge of adult forms is available it seems 

 more convenient to assign the higher rank to van Beni di n's groups and to recognize in the 

 Ceriantheae two suborders, the Acontiferae and the Botrucnidifera;. The latter will contain the 

 genera Cerianthula, Hensenanthula, Calpanthula and Botryanthus, while the former may agajn 

 be divided into the two families mentioned above, the Cerianthidae containimr the genera 

 Cerianthus, Apiactis, Solasteractis -) and Peponactis, and the Arachnactidae containing the genera 

 Arachnactis, Pachycerianthus, Dactylactis and < )vactis. 



No Botrucnidiferae occur in the present collection. 



Suborder ACONTIFERjE van Beneden. 



Ceriantheae in which the second or fourth protocnemes, or in some cases both these mesent- 

 ar<- provided with acontia at least during the early stages of development. The deuterocnemic 

 marginal tentacles appear in the same order as the mesenteries to which they correspond. 



Family Cerianthid e. 



Acontiferae in which the second couple of protocnemes are the telocnemes. The succeeding 

 protocnemes are represented by a brachycnemic couple, usually sterile, and by a macrocnemic 

 couple. Acontia are borne in larval stages upon the telocnemes and in some cases also upon 

 the macrocnemic protocnemes. 



i) Tliis marked dilTerencc in the distribution of the botrucnidse in //. dactyliftra from what obtains in the other two species 

 i>ility that it mif;ht be well t ■ » regard spinifer and melo as representatives of -\ liUtinct genus. 



that the form of the tentac^ of da< renl ir whal is shown for the other two spi 



Ihe ac mtia has nol yel Ijeen determin ictis, which K known only fr.im a single 



i oot dcveloped. The genus may eventually require transference to the nunily Arachnactidse. 



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