and AcajJulco SpoJiges. 279 



" Section 2. 



" Orifice du Siphon plutot frange que cilie. 



" Section 3. 



" Orifice nu, c. a, d. n'offrant ni cils ni pinceaux bien 

 formes, ni frangds." 



To these sponges Schmidt has given the name of " Sq^ho- 

 iwcJtalina,^^ and, after enumerating several of them (Spongf. 

 Athintisch. Gebiet. p. 34), adds that they present " an un- 

 broken line of varieties." 



The grou[)S Spinifera, Aculeata, Subaculcata, and Ciliata, 

 in my classification, were intended to receive the whole of 

 de F. et M.'s genus Tuba ; the three latter in the second 

 family, viz. Cavochalinida, and the former in the first family, 

 viz. Chalinida; hence Tuba annijei-a, being solid, should have 

 been inserted next to Chalina rubeiis among the Chalinida, 

 but has been placed here for convenience. A few words, 

 however, will show how tlie solid form of Ghalina may pass 

 into the hollow one. Thus, when the cylindrical stem is solid 

 and erect, the vents are on the surface or outside; while if 

 tlie stem is repent and the vents grow upwards into iioUow 

 tubes at the expense of the repent portion, then the vents 

 of the erect portions open into the interior or inside of the 

 tubes, and the . pecimen thus becomes a Cavochalina ; but if 

 the vents of the repent portion do not grow upwards in this 

 way, then the species remains solid, increases in size, and 

 of necessity comes into the first family, or that of solid Ghallnai; 

 hence our Tuba armigera; falls into the group Spinifera. 



Tuba acapalcaensisj n. sp. 



]\Iasslve, globular, lobed, erect, consisting of a group of 

 short branches anastomosing with each other as they grow up 

 into the form mentioned, more or less extending beyond the 

 circumference, aculeate, solid, or hollow. Consistence resi- 

 lient. Colour dift'erent shades of fawn. Surface of the 

 branches more or less aculeated, aculeations consisting of 

 spiniform prolongations of the fibrous structure. Vents on the 

 surface of the solid branches, opening into the interior in the 

 hollow or tubular ones. Internal structure fibrous, resilient ; 

 fibre chiefly kerasine flexible, cored or axiated by the spicule 

 of the species in different degrees of plurality. Spicules of 

 one form only, viz. acerate, variable in size, chiefly confined 

 to the fibre. Size of largest specimen, of which there are 

 iipwards of a dozen, about 6 inches in diameter ; largest 

 branches about one third of an inch thick. 



20* 



