19 



7. BLOTHROPHYLLUM DECORTICATUM (Billings). 



(Plate IV., Fig. 3.) 



Blothruphyllum decorticatum (Billings) : Canadian Journal, New Series, Vol. IV., p. 130, 

 Fig. IT). 



"Adult specimens, two feet in length, and three inche- in diameter ; dimensions of the 

 immature individuals, variable ; usually slender and irregularly curved ; <>uN-r area con-i-ting 

 of rather strong rudimcntarv transverse diaphragms, curving' upwards ami outwards, di.-tant 

 from two to eight lines. bearing upon their upper ^urfacfs impert'eet radiatii . which do 



not extend from one diaphragm to nnotl.fr. The-, septa are hail' a line di.-tant at the mar- 

 gin of 4 specimen three inches in diameter. When the epitheoa i- pre-erv.-d. \<\<- surface of 

 thi- ia marked by numerous deep simulations ami -h -\\ p encircling folds, their e.' 



being always on the upper side. The transverse diaphragms in ihe central area are nearly Hat. 

 but have a -trong sept.-il fo--efte upon one .-ide " ( Iliilin.. 



In the examples which I am d'spo-ed to refer to thi- species, tin- arched tabuke oi' the 

 outer area are not less than two lines apart, oft-n from a ijuaru-r to half an inch, and the 

 tabulfe of the central area are also distant. The central tabula- are often ijuite !lexu"us. hut 

 are never elevated into a boss ; most usually they arc nearly flit. The .-epta which spring 

 from the upper surface of the arched tabula- of the outer area only reach the tabula- imuiedi 

 ately above in the inner portion of the area in ijue-tion ; but in the outer portion ^me 



area fall far short of the tabuln? above, owiii'_ r to the tact that the tabula- are -ironjy arched. 

 and have their concavities directed toward- the ba-c ol' th>- coral. The concave under -ur- 

 faces of the tabulae of the external area pre-.-nt. however, well-marked ridges corresponding 

 with the septa on the upper surface. The sfpta on the upper surl'aco of the tai-ui;" \.u-y 

 from half a line to a line in distance from one anoth--r, hut there are very generally i'ltercal- 

 nfi-d 1" -tween the larger -epta smaller ones, one between each pair, which have simply the form 

 oi' -lightly elevated ridges. The epitl,. e-i j- n,,t only marked with encircling aiiiiulation- and 

 folds of growth, bu1 also with di.-tinct longitudinal grooves, five in tb 'twoli; 



The epiweoa, however, is rarely pn-crved. and specimen- occur ino-t conim nly in one OI 

 Other of two conditions. Hither the epitheea In- ln-en reino\ed, e\pn-iiu [o \i.\vthe 

 arched tabiihe of the outer ;uva with tin- imperli-c| -ep;;i on their upper surface- ; or the entire 

 outer area has been removed along with the epiiheca, leaving the central and intermediate 



areas in tin' form of a core tu tl ut-ide of which are attached th bases of the arched 



tal'iil;" n|' tli-- oiitf area. Thi- gives ri-e to an ap]H-arance which i- OXd edingly characteristic 

 of th" pre-i nt | and hy which it can almo-t he infallibly iveogni/rd even in very inn 



feet exam files. 



Locality a nation. Common in the Cornilerous Lime-tone of i 



HH villc. and at nnny other puint-^ wh'-n- tlie lormation i.- i-xpo-- 



S. P.I.nTIIKiU'IIYI.J.I'M AI'I'ltnMMATI'M (Nichol-oii). 



lab IV., I 

 Blothrophyllum ap} "Canadian Naturalist," Vol. \'ll.. \ 



I 'oi-alluni of unknown length, Cylindrical. The outer ar. 'ingo! 



diaphr- upward- itwird- <h i.nt from one another from half a In; 



two lini -, liearing ii|"'n tln-ir nppi-r .-url'aet- imperli-et -epta wlneli extend from on. 



In r when tin- t-ibul.i MM- f'Tini r distance only, but whid 



mall, di-t-int about a tliinl of :i |i;i > ihe 



c.-iitr::] ar--:i do- ly approximated, from thn-e to liuir iii tin- :' two In Stly 



pta onl\ -lightlv i nei-o;n-! .,, them. Kpitheca \\itli nun 



tioi . ihand fiii-ireling :,nn and obscure l"n>- i I iidinal -In I 



unknown, but e.-n.iinly a;i 



I n Hi' ntial e!, ill, 



(BillingB,) Of which perlni rely a ^ariei 1 by i: 



rally much giv.-it.-r .-!/.' and by tin- app-in-ntly . : peculiarity ihat tin- tabula "I 



out' ip- Very e. :iueh n, .11 ill /.' Tl . t\ | i al 



