614 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 14 



If the Trepostomata are not to be included in the same order with 

 the Cyclostomata, there appears to be no good reason for the use of the 

 new name Stenolaemata and, at least until there is substantial confirma- 

 tory evidence on this question, I prefer to continue the use of "Order 

 Cyclostomata." Marcus (1941:12) suggested the name Stenostomata 

 to replace Cyclostomata, which has been used also for a group of verte- 

 brates, but since the rules of priority are not concerned with ordinal 

 names, there seems to be no very good reason for substituting a new 

 term for one which has been well-known and acceptable to zoologists 

 for a century. 



Borg's separation of the Cyclostomata (1944:20) into five divisions, 

 based on anatomical studies, follows closely that of older authors and is 

 logical and well-founded, but he seemed to think it necessary to set up 

 a whole new series of divisional names. Since it appears that Borg 

 simply confirmed, by added histological evidence, the distinctions already 

 made in the past, there seems to be no necessity for the discarding of 

 well-known terms and the coinage of a new series of div^isional names. 



The following table gives a brief digest of the essential characters 

 of the five divisions of the Cyclostomata under the old established names, 

 with those of Borg in parenthesis, to indicate the synonymy. 



1. Zoarium adnate, suberect or erect, never jointed, the first few tubules, 

 at least, always adnate. Wall of the zoarium simple; the ovicell a 

 gonozoid varying from simple to broadly expanded and often lobate, 

 its polypide degenerating after first reaching maturity. Tubuliporidae, 

 etc. (Acamptostega Borg, 1926). 



Tubuliporina Hagenow, 1851. 



2. Zoarium slender, erect from the first zoid, always jointed, branched, 

 rhizoids present. Wall of the zoarium simple; gonozoid simple (some- 

 what expanded in Crisulipora) , its polypide degenerating before 

 reaching maturity. Crisiidae. (Camptostega Borg, 1926). 



Articulata Busk, 1859. 



3. Zoarium erect from the beginning, branched tree-like or wine-glass 

 shaped, never jointed. Wall of zoarium double, increasing in thickness 

 throughout life; gonozoid strongly dilated and usually situated more 

 or less on the dorsal side. Horneridae, etc. (Pachystega Borg, 1926). 



Cancellata Gregory, 1896. 



4. Zoarium usually erect, sometimes adnate, often cylindrical and branch- 

 ing, composed of autozoids and kenozoids with the apertures of both 

 at the surface. Wall double; brood chamber zoarial formed by the 



