45 



ACALEPH.E. 



with a single rounded aperture communicating with a single deep 

 cavity, towards the end of which is a granular corpuscle. 

 Example, Pyramit tetrayona (Otto). 



ture, with a[ 



a very long and blind ca- 



Example, Sulculeolaria 

 ranean (Nice). 



ACALEPH.E. 



two extremities, with a posterior aper^ 

 ?u its circumference, and leading into 



sueur). Locality, Mediter- 



i-' 



Diphyct JJory. 



1, the entire animal (profile) ; 1 fl, anterior part of the same; 1 &, posterior 

 part ; 1 c, animal magnified ; 1 d, posterior part of the same. 



M. Eschscholtz makes this organised body a species of his genus 

 ia, which comprehends Cucubaltu and Cucullat of Quoy and 

 Gaimard, admitting that the two nata- 

 tory organs are ultimately united so as 

 to form, apparently, but one. 



2. Praia. 



Body subgelatinous, rather soft, 

 transparent, binary, depressed, obtuse, 

 and truncated obliquely at the two 

 extremities, hollowed into a cavity ryram'u tetragona. 



of little depth, with a round aperture nearly as large as the cavity, 

 and provided with a largo canal or furrow 

 above. 



Example, Praia duliia (Quoy and 

 Gaimard). 



3. Tetragona, 



Body gelatinous, transparent, rather solid, 

 binary, of an elongated, parallelopiped, tetra- 

 gonal form canaliculated below, truncated 

 nl>lii|iiely anteriorly, pierced behind by a gaping 

 orifice furnished with symmetrical poiuta, and 

 leading into a long blind cavity. 



Example, Ti/ragona hiepidum (Quoy and 



aimard >- Praia dMa. 



I, Trtraguna liitpidum ; 2, 3, 4, details of the same. 



4. Xulculeolaria. 



Body frabcartilaginoiw, transparent, elongated, cylindroi'd, traversed 

 throughout its length by a very large furrow, bordered with two 



Sulciilt'olaria quadrivalris. 



A genus characterised by De Blainville, who found it established in 

 the figures of Lesueur, from those figures ; but the former is strongly 

 inclined to believe that the genus is founded on the part of an animal, 

 and not on an entire one. 



5. GaJcolaria. 



Body gelatinous, rather firm, perfectly regular, symmetrical, sub- 

 polygonal or oval, compressed on the 

 sides and furnished with two lateral 

 rows of extremely fine cirrhi. A large 

 posterior aperture pierced in a sort of 

 diaphragm with appendicular lobes, 

 binary above, leading into a large 

 cavity with muscular walls. An ovary 

 at the anterior superior surface, 

 coming out by a mesial and bilabiated 

 orifice. 



Example, GaUolaria australis, Seroldca 

 australi* (Quoy and Gaimard). 



6. Bosacea. 



Body free, gelatinous, very soft, trannparent, suborbicular, with a 

 single terminal aperture at one of the poles leading into an oval cavity 

 which communicates with a depression, whence proceeds a cirrhiger- 

 ous and oviferous production. 



Example, Bosacea Cewtenxis (Quoy and Gaimard). 



Galcolaria australis. 



jRosacea Cciitcnsis. 



7. Noctiluca. 



Body free, gelatinous, transparent, spheroidal, reniform, with a sort 

 of infundibuliform cavity, whence proceeds a proboscidiform contractile 

 production. 



Example, Noctiluca mttiaris (Lamarck). 



M. Surriray, a doctor of medicine, while investigating the cause of 

 the phosphorescence of the sea-water at Havre, appears to have been 

 the first who observed and 

 called attention to the genus 

 Noctiluca, which he described 

 and figured in the memoir 

 that he communicated to the 

 class of sciences of the French 

 Institute. Its size hardly 

 equals that of a small pin's 



head, and it is as transpa- Ifoctlluca miliaris. 



rent as crystal ; he found it 



very common in the basins at Havre, sometimes in such abundance 

 as to form a considerably thick crust (croute assez dpaisse) on the 



