1 8 Coelenterata. 



a pedal disc, for the physa is chiefly used in boring and is but a feeble organ 

 of fixation; in the Ilyanthidse (which form the majority of the Athenaria) the 

 absence of basilar muscle is closely correlated with the sand-burrowing habit. 

 In Halcampoides abyssorwni the so-called parietal muscle is homologous whit 

 the parieto-basilar of Tealia but has attained a great development and reaches 

 the distal part of the body. In some of the higher Actinise this muscle ex- 

 tends, as a small lamella, to the distal end of the body. The basilar muscles 

 in the Actinise arose phylogenetically later than the parieto-basilar and parietal 

 muscles. The lower forms (Protanthese, Athenaria and the Discosomidse among 

 the Stichodactylime) have no homologue to the basilar muscles, which develop 

 only with the growth of a true creeping sole. In the Athenaria the parietal 

 muscle, which is found on the same side as the transverse muscles, is homo- 

 logous to, and a further development of, the parieto-basilar muscle of the higher 

 Actiniaria and Protanthese; the parietal muscle which lies on the same side 

 of the mesentery as the longitudinal muscles is probably only a differentiation 

 of the longitudinal muscular layer and has its homologue in certain stronger 

 muscle -folds which are only occasionally found in higher Actiniaria (in the 

 elongate forms) on the edge of the body wall. 



Clubb describes the anatomy of Urticina sulcata (20-44 fms.) and carlgreni n. 

 (20-28 fms.) from Cape Adare, South Victoria Land. In female specimens of 

 sul. the body wall in its upper third is thinner and the verrucse (which are 

 elsewhere present in 48 vertical rows) are almost obliterated by longitudinal 

 furrows. Male sul. and all carl, show this modification to a less degree. 

 There are 4 cycles (6. 6. 12. 24) of tentacles, 3 cycles (6. 6. 12) of mesenteries, 

 all of which are complete, and all are fertile except the two pairs of directives. 

 The adult Q possess brood chambers completely separated from the ccelen- 

 teron and formed by invagination of the body wall. There is, at first, a series 

 of these invaginations 2-3 mm. deep; as these enlarge the partition walls 

 between adjacent invaginations break down until only 4 (in side.) or 6 (in carl.} 

 large cavities remain. After the fertilised ova enter these cavities the latter 

 become closed. The young embryos are irregular in shape being moulded 

 to each other and to the contour of the chamber in which they lie. When 

 the young anemones have 3 cycles of tentacles and mesenteries (one cycle com- 

 plete) and have reached a diameter of 10-15 mm. the brood pouches again 

 open to the exterior by a slit which extends more than halfway round the 

 body, and thus the young anemones escape. In one carl, in this condition new 

 invaginations were found between the old brood pouches, suggesting the brood 

 chamber serves only for one embryo and that on its escape the walls of the 

 chamber atrophy and new chambers are formed for the next brood. 



Gravier describes Dactylactis benedeni n. found in the surface waters of the 

 Gulf of California [see Bericht f. 1902 Coel. p 18]. The buccal tentacles are 

 in two alternating cycles, those of the outer cycle being a little longer; there 

 is at one end of the long axis of the stomodseum a rudimentary tentacle, this 

 together with 11 or 12 on each side makes a total of 23 (10 internal and 

 13 external), 24 or 25. The marginal tentacles are one more in number than 

 the buccal. The siphonoglyph is at the end of the stomodseum corresponding 

 to the missing buccal tentacle, it is prolonged into the coelenteron as a gutter 



the hyposulcus (van Beneden); there is no sulculus. There are gland cells 

 in the stomodseum. The marginal tentacles, which play an active part in the 

 capture of food, are richly provided with uematocysts. The animal is her- 

 maphrodite, male organs are more abundant in the upper part of the fertile 

 mesenteries, female organs are more abundant in the lower part. The animal 



