U)() ACTINLE OF ALBATROSS EXPLORATIONS TMCMURRlCH. 



('ntci'y (x'l'iipied by it as it does in />. jXdiuoNo. Tlio iiuisculiituic of the 

 rest of tlio execi'lic surface is for the most i)art <»l»lique, becominji' for 

 a short distance transverse, and linall.x , as in />'. jxnniotui, becouiin^'; loii- 

 liitndinal. The };eueral arraniieincnt <»f the nmscidature tlierefore 

 aiLirecs closely Avith tliat of 1i. ixoinosa, tiie main ditfercuec being the 

 absence of cavities in liic mesogheai of the parietobasilar region. 



Thisform Isoimm)!' cDnsiderableintercst. W'lien 1 lirst saw it in glanc- 

 ing over the collection, 1 believed I liad Itclbre me a specimen of llert- 

 wig\s Liponenut mxltiponmi ('SS). The ])rescnc(^ ol' the tentacles, 

 however, induced me to belicNc that 1 was wiong in this supposition, 

 but the general similarity in ai)pearance suggested th«'. idea that [)0S- 

 sibly TIertwig's sjx'cinuMis were identical with lliis, bat liad Inst all their 

 tentacles. When I had finished my study of the anatomy of />, hrrri- 

 coniis, I perceived that t his idea Avas not (juite correct, but tiiat though 

 the two forms can not be considered identical sp<'cifically, yet they are 

 so closely related as to warrant the conclusion that they belonged to 

 the sanu' genus, and that Ijiponcma multiponim isai llolinrrn which has 

 lost all its tentacdes, 



Tu anyone who has followed my description caretully and has 

 comi)ared it with that of Ijipmuma, I think the similarity between the 

 two forms will be apparent. There is tiie same geiuMal appea.ran<'e, the 

 sanu' folding back of the volununous disk, the same '"stomidia" almost 

 covering the disk (though in the AUxdrosfi form these are normally sur 

 mounted by tentacles), the same circular fold at the margin, the same 

 longitudinal lines on the column, a similar (h)ubleendodei'mal s])liincter, 

 the two muscles being separated by ])ouchings out of tlu' column \\ all, 

 the same (liscrepan(5y between theiuunber of mesenteiies ami tentacles 

 (or stonudia), and a close similarity in the arrangement of the perfect 

 and imperfect mesenteries. 



These similarities are, I think, sullicient to mark the two forms as 

 beh>nging to the same genus. The different shape of the marginal 

 sphincters and the slight difference in the arrangenuMit of the mes- 

 enteries leads to their assignment to distinct species. 



It is worthy of note, too, that Ilertwig describes a sphincter fidd 

 ch)sing the openings on the disk, the "stonudia." This reminds me 

 strongly of the nuiscular fold in the tentacles described in (he preceding 

 S])ecies of Boloccro. Taking all the facts into considnatictn, 1 believe 

 that Hertwig's Lijxmcma muU'qmyutn should henceforth be kiu)wn as 

 Boloccra m uUipora. 



Fandly PARACTID.E, II. Hert. 



Actinia' usimlly with mimerous perfect mesenteries; circular nniscle 

 strong, imbedded in the mesoghea: acontia wanting. 



The family Paractida-, was established by K. Hertwig ('SL') on ana- 

 tonncal grounds, the forms lu'longing to it having been i)reviously 

 associated for. the most i)artAvith the Antheada'. Jn the above delini- 



