FLORIDAN BRYOZOA. 23 



Nevertheless, the Floridan specimens of Cribrilina innominata, brought up by Pourtales, 

 have all their zooecia of a smaller size. ■ — ■ I have raeasured the breadth of the aperture 

 to about 0,06 mm. — ; but this difference, when vve have seen all the variations, in 

 this respect, of the preceding form, here can be of no specifical value. Yet, as long 

 as we do not know the true physiological significance of the named pore, leaving it 

 for further inquiry, we can make no better than to retain it as a character for system- 

 atical distinction. 



Pourtales has taken the Cribrilina innominata, growing on Nulliporse and on 

 a piece of a dead shell, in various depths from 29 to 60 fathoms. 



Cribrilina jigularis 1 ) (Pl. V, hgs. 111, 112). 



In the preceding species, when we have seen such differences as that between figs. 

 109 and 110, taken from different parts of the same colony, we may well be prepared 

 to find the Cribrilina jigularis varying in the same degree. Pourtales bronght up two 

 colonies of this species, the one (tig. 111) growing on a piece of shell, at 29 fathoms, 

 the other (fig. 112) on a piece of coral, at 42 fathoms. In the first, the species has 

 its typical appearance, as described by Johnston and Busk, except that the mouth of 

 its zooecia is provided with a pair of marginal spines, which, sometimes, are bifurcate. 

 Now, the presence or absence of marginal spines at the aperture scarcely can make 

 any specifical difference, because it is a developmental law for the Escharines, particul- 

 arly of this group 2 ), in their higher development to lose them. But, with our pre- 

 sent knowledge, as they seern to be constant in the Floridan form, in connexion with 

 the greater pores and more marked ribs of the zooecia, they will be accounted for 

 enough, by giving this form a separate name, Cribrilina ftoridana, as a local variety. 

 Unfortunately, on this colony no ocecia are developed, and then we are unable to say, 

 if the mouth of the so-called fertile zooecia, also, is provided with marginal spines 3 ). 

 As to the size of the zooecia, I have measured the breadth of the mouth to about 0,ir> 

 mm., which seemed to be the most common size. 



The other colony, taken by Pourtales, is more highly calcified, whereby the 

 pores are rendered smaller and the ribs, proportionately, more leveled. Thus, this 

 colony is more advanced towards the appearance of Cribrilina annulata. That same 

 we have seen to be the case with the two preceding species (figs. 108 and 110). In 

 considering the systematical significance of the interesting variety of Cribrilina -punctata 

 from Gibraltar 4 ), Busk, also, regarded this as the most perfect state of that species. 



') Lepralia jigularis, Johnst., Brit. Zooph., ed. 2, p. 314, tab. LVT, fig 2; Gray, Cat. Brit. Mus., part. I, 

 Rad., p. 119; Busk, Cat. Brit. Mus., Polyz., p. 80, tab. LXXIII, figg. 1—3; Smitt, {Escharipora) Erit. 

 Fört. Skand. Hafsbryoz., Öfvers. Vet. Akad. Förh. 1867, Bih., p. 4. 



-) Erit. Fört., Öfvers. Vet. Akad. Förh., 1867, Bih., pgs. 52 and 54: 



:! ) As to the form of the ocecia, which, in this group, seera to be very useful for the specifical distinction, 

 the figures given by Busk, seern to indicatc a very low degree of calcificatiou, because on a specimen in the 

 British Museum I have seen the ocecia of this species to be almost of the same form as those of Cribri- 

 lina punctata fignved by Busk, in his Crag Polyzoa (Pl. 14, fig. 1), except that they were more rounded 

 and showed a rib, also, from the mucro, descending proximally to the middle of the apertural margin. 



4 J Lepralia punctata, Quart. Journ. Micr. Se, vol. IV, p. 310, Zoophytol., Pl. XI, figs. 4, 5. 



