56 zoological collections made during [jan. 4, 



Cyclostomata. 



Idmonea milneana, d'Oi'bigny. 



Idmonea milneana, d'Orbigny, Voy. Amer. merid. p. 20, pi. ix. 

 figs. 17-21; Busk, Cat. Mar. Polyz. Brit. Mus. pt. iii. p. 12, 

 pi. xi. 



Tululipora transversa, Lamarck?, Anim. s. Vert, (l)ii. p. 162. 



Idmotiea transversa, M.-Edwards?, Ann. Sci. Nat. (2) ix. p. 218, 

 pi. ix. fig. 3. 



This is certainly the species described and figured by Busk. His 

 description requires emendation by the substitution of "thin" for 

 "thick" as a character of the margin of the cells, and by the 

 insertion of " a long backvvardly directed spine on the l)ack of the 

 main and sometimes of the smaller branches." One such spine, and 

 perhaps the trace of another, broken off, occurs on the specimens 

 already in the Museum. In the two relatively smaller specimens in 

 this collection they are more abundant ; in one case the two primary 

 divisions of the stem each bears one ; and of their branches, one of 

 the one and both of the other bear them. They are strong ; and the 

 maximum length appears to be about 3 millims. As pointed out by 

 Haswell (Proc. Linn. Soc. N. S. Wales, iv. p. 351) in a specimen 

 assigned by him witli doubt to this species, the " dots " of Busk's 

 description are certainly raised. But the truth lies between the two ; 

 for they are also perforated in their centre in the original British- 

 Museum specimen and the Magellan one. The alternating character 

 of the lateral series of cells, which is very slightly marked in the 

 Patagonian specimens ahuded to (from which the account in the 

 British-Museum Catalogue was in part written), and which is almost 

 lost sight of in d'Orbigny 's account, is here strongly marked. The 

 longitudinal striation and the concentric lines on the back are also 

 well marked here. 



Hab. Tom Bay, near Madre-de-Dios Islands, S.W. Chili, 0-30 

 fathoms, embedded in base of a horny Sponge, partially overgrown 

 by Lepralia monoeeros and a creeping calcareous Sponge. 



Obs. This may possibly prove, as Busk says, to be I. transversa, 

 Milne-Edwards ; but the habit of growth as figured by M.-Edwards, 

 and the locality (Mediterranean) as given by Lamarck, are against 

 the idea. 



Smitt, in his 'Floridan Bryozoa,' remarks on this species that 

 the typical number of cells in the transverse rows is three, varying 

 to two or even one in the lower parts. In the present specimens 

 the number never falls below three, and is as often four as three, 

 if not oftener. He has also observed "radiciform pillars" at the 

 back of the branches of one of his specimens ; but there their ends 

 were expanded into clasping processes and attached it to a foreign 

 body, whereas in the Chihan specimen they end simply. 



Diastopora patina, Lamarck. 



Tubulipora patina, Lamarck, Anim. s. Vert. (2) ii. p. 244. 

 Diastopora patina, Smitt. CEfv. K. Vetens. Ak. Forh. I86C, 

 p. 397, pi. viii. figs. 13-15. 



