Tlie Actiiiiae of tlie Plate CoUectioii. 255 



B. iunUicornis. Otlier species were later describetl by Carlgeen, 

 KwiETNiEwsKi and myself, biit until quite receiitly iio one liad 

 l)roposed new geiieric names for any of tlie species, notwithstanding 

 tliat considerable differences were observed in tlieir structiire. In 

 1900, liowever, Carlgeen liad an opportnnity for stndying a species 

 from Zanzibar, whicli proved to be identical witli tliat from Amboina 

 previously described by Kwietniewski (1898) as B. mc nmrricM, 

 and, observing that it possessed well developed ectodermal muscles 

 in the column wall, established for it a new genus Boloceroides and 

 transferred it to bis tribe Protantheae. I have made re-examination, 

 with Carlgeen 's Observation in mind, of all tlie species of Bolocera 

 of wliich I have examples and find tliat in B. hrevicornis tlie ecto- 

 dermal column muscles are also quite well developed. Tliis form 

 must accordingly be associated witli B. mcnmrrichi in the genus 

 Boloceroides, for it seems advisable to retain the genus even although 

 one may not be able to agree Avith the tribal position to which 

 Carlgren assigns it. 



A division of the original genus being thus initiated, the 

 question arises whether it should not be continued still further. I 

 have long thought that some subdivision was necessary, but the 

 relatively small number of specimens examined seemed a reason for 

 waiting until more extensive observations had given a surer basis 

 for Classification. The discovery of the form to be described below 

 seems to demand a new genus, since it lacks the tentacular sphincter 

 so characteristic of other species, wliile in other respects it is a 

 typical Bolocerid. I propose to establish for it the genus Bolo- 

 veropsis. 



Another genus miglit well be established for B. poUens, in 

 which I found (1898) a strong circumscribed sphincter instead of 

 the more usual ditfuse or aggregated one, but this may well be left 

 for further observations to determine. 



Genus JBoloceropsis n, (j. 



Bohceridae wäth rigid tentacles not provided Avith a sphincter; 

 no longitudinal ectodermal musculature in the column Avall. 



12. Holocevopsls i^Uitei n. sp. 



No. 22. Calbuco. 16—20 fathoms. 1 specimen. 

 232. Calbuco. 10 fathoms. 4 specimens. 



