PHYSALIIDAE. 321 



They recognize two genera, Pterophysa, in which the siphons are sessile, i. e. 

 attached directly to the stem, and Bathyphysa, in which they are borne on long 

 pedicles. Judging from their descriptions this distinction seems to be a valid 

 one. The minor features such as might be expected to serve for specific diag- 

 nosis within the two genera are still but little known, the only species sufficiently 

 well described being Pterophysa grandis Fewkes (Lens and Van Riemsdijk, :08). 

 The "Albatross" collection throws no light on the question. 



There are two known species of Bathyphysa, B. abyssorum Studer, and B. 

 sibogae Lens and Van Riemsdijk. We may safely assume that these two are 

 distinct because the latter authors were able to examine Studer's original speci- 

 men. 



In Pterophysa there are P. (Rhizophysa) conifera Studer, P. {Bathyphysa) 

 grimaldii Bedot, and P. grandis Fewkes. These three are so closely allied that 

 I doubt whether they can be distinguished. Finally there is the Pterophysa 

 {Bathyphysa) studeri of Lens and Van Riemsdijk, which the describers were 

 unable to class definitely in either genus. 



The Bathyphysinae are represented in the present collection by some frag- 

 mentary segments of the stem with a few siphons attached. They can not be 

 identified, except that the presence of pedicles throws them into Bathyphysa 

 rather than into Pterophysa. 



Bathyphysa species ? 



Station 4645 300 fathoms to surface on sounding wire ; fragments. 

 " 4689 " " " " " dredging " 



" 4724 800 " " " " " " " 



Physaliidae Brandt, 1835. 



I follow Chun ('97b) and his successors in recognizing only a single genus 

 of this family, Physalia. The three other genera diagnosed by Haeckel ('88b), 

 are merely as many stages in its development, as Chun's ('87b) earlier work had 

 shown. 



The early history of Physalia has been given in much detail by Chun ('97b). 

 As is well known, the genus, long accepted by zoologists in general, was founded 

 by Lamarck (1801) for the Holothuria physalis of Linne (1758). Gill (:07), it 

 is true, has recently maintained that this species must be regarded as the type, 

 not of Physalia, but of Holothuria, in which it was the first example mentioned 



