296 
Z. ASCIDIOIDA. 
Retepora. 
often blackish and emitting- fibrous radicals ; the intervening spaces 
long, cylindrical, frequently swollen near the upper end, covered all 
round with lozenge-shaped immersed cells, disposed in quincunx, and 
radiating from the centre. 
In a weak mixture of muriatic acid and water, the calcareous por- 
tion of the polypidom is entirely removed without any other altera- 
tion in its form and structure, and we learn from the experiment that 
the joints are connected together by capillary corneous tubes, equal 
in number to the series of cells. These tubes cannot be traced 
through the immediate spaces, but from the circumstance of their 
being hollow, it seems not unreasonable to infer that they may na- 
turally be filled with an irritable pulp, and be the medium of com- 
munication between the cells and polypes of the different interspaces. 
The branches are not tubulous or fistular, as Blainville has properly 
remarked ; whence the impropriety of the Linnsean trivial name, the 
retention of which only tends to the perpetuation of error. 
Under this species Pallas has the following interesting observation : 
“ Celerrime hanc Cellular iam crescere, saltern celerius embryone 
Squali, docuerunt ova Squali Promontorio merid. Africes allata, in 
quibus plantulas plures semipollicares observavi, quanquam fcetum 
adhuc immaturum continerent.” 
38. Retepora,* Lamarck. 
Character. — Coral foliaceous , stony , fragile , netted : cells 
opening only on the upper or inner side , short and not prominent . 
— Polypes ascidian. 
1. R. reticulata, polypidom latticed , wavy and convolute, the 
upper side warty and very porous. Rev. William Borlasse. 
Millepora retepora, Borl. Cornw. 240, pi. 24, fig. 8. Millepora reticu- 
lata, Lin. Syst. 1284. Fabric. Faun. Groenl. 433. Ellis and Soland. 
Zooph. 138. M. frondipora, Pall. Elench. 241. Retepora reti- 
culata, Lam. Anim. s. Vert. ii. 182. 2de edit. ii. 275. Risso , L’Europ. 
Merid. v. 343. Flem. Brit. Anim. 531. Stark , Elem. ii. 435 Re- 
tepore reticulee, Blainv. Actinolog. 633. Frondipore reticule. Ibid. 
406, pi. 69, fig. 1. 
Hah. Deep water, rare. Cornwall, Borlasse. 
u Expanding to the extent of 2 or 3 inches ; more or less cup- 
shaped, waved, uniting ; the lobes are oval, regular, the intervening 
spaces supporting two or three pores in oblique rows. This species 
* From Rete and Trogof, i. e. a “ a porous net-work.” 
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