")92 SUMMARY OF CURRENT RESEARCUES RELATIXQ TO 



of au nttacbcJ fuugus growth, were observed. By the aid of a lens tlio 

 attached body was seen to be a Ilydroid, for which the name oi nijdrichthja 

 mirus has been ])roposod, The hydroid forms consist of sexual and asexual 

 individuals, the latter of which are simple flask-shajied bodies without 

 tentacles and with terminal mouths ; they may be called filiform bodies, 

 and the sexual persons gonosomes. Neither have a circle of tentacles 

 around the mouth-opening. The medusa-stage (gonophore) has a Sarsia- 

 like bell and manubrium, four radial tubes, and four tentacles without 

 ajipendages. 



The loss of tentacles by the hydroid may be ascribed to the parasitic 

 habit. The relation of the medusoid to the Sarsia-liko group implies 

 degeneration and not phylogeuetic simi)licity. The polymorphism of the 

 hydroid stages is also an important character. Ilydrichthi/s appears to 

 be the nearest known ally of Vehlla. Mr. Fewkes thinks that we may 

 learn from the present case that the true affinities of most Hydroids 

 cannot be definitely made out until both Ilydroid and Medusa are 

 studied together. 



Medusae from New England.* — Mr. J. W. Fewkes gives an ac- 

 count of the MedusPD observed on the coast of Maine and at Grand 

 IMauan. The only Physophore captured was Nanomia cam, of which 

 little is known ; the author was able to make some observations on its 

 development, and to see that the primitive larva jireserves the Medusa- 

 form ; it " may be supposed to approach more closely the ancestral form 

 of the Siphonophora among other Hydromcduspe than any other medusi- 

 form larva." The close homology between a medusiform gonophore 

 and a simple hydroid is such that the author thinks we are justified in 

 regarding the young of Nanomia with a float and no primitive hydro- 

 phyllium as analogous with the primitive larva of Agahna. Mr. Fewkes 

 believes that the ancestral form of all Hydromedusaj, as well as of all 

 the Siphonophora, will be found to be similar to the primitive larva of 

 Agahna in its youngest stages. It had the form of a ciliated placenta, 

 with an enlargement at one end and a mouth at the opposite. The 

 enlargement at one end was formed of three layers, wall bell-shaped or 

 gelatinous, and it is this which forms the bell of the Medusae, the float 

 of Nanomia, and the primitive hydrophyllium of Ayalma. In the fixed 

 hydroid it becomes a base of attachment, in Illuzojjhijsa or Nanomia a 

 float, and in Agahna a covering scale. 



Uijdricldlvjs minis is a new genus and species, for which see supra. 

 The remarkable genus CalUnema was rediscovered by Mr. Fewkes, who 

 gives some notes on the anatomy of C. ornataum\ ; he does not agree with 

 Prof. Haeckel in thinking that it belongs to the genus Phacellojjhora. 



New Physophore.f — Mr. J. W. Fewkes describes a new genus of 

 Physophorids — Pheophjsa — which has interesting morphological affini- 

 ties with already known genera. The large float is partially covered by 

 a hood-shaped body which is (or appears to be) bound by muscular bands 

 to a globular enlargement of the polyp-stem. There are no nectocalyces 

 nor hydrophyllia. The form of the stem (axis) which ordinarily bears 

 polypites, is reduced to a globular shell, and tlie nectostem, or part which 

 ordinarily carries nectocalyces, is modified into the hood. P. agassizii 

 is the name of the species. 



♦ Bull. Mus. Comp. Zool. Camb., xiii. (1SS8) pp. 209-40 (6 pis.). 

 t Aim. and Mag. Nat. Hist., i. (1888) pp. 317-22 (1 pi.). 



