PORIFERA. II. 



173 



Note. This species has a skeletal structure similar to that of the species ternatensis established 

 by Thiele (Abhandl. d. Senckenberg. nat Gesellsch. XXV, Heft IV, 953), and by him referred to the 

 genus Hamigcra. The genus Hamigera with the typical species hamigera 0. Schmidt was by Top- 

 sent (Resultats des Campagn. scient. du Prince de Monaco, Fasc. II, 102) referred to the Ectyonina on 

 account of its skeletal structure. Thiele I.e. says that, after having examined sections of Schmidt's 

 type specimen, he cannot follow Topsent in this, as he finds styli and strongyla to be intermingled. 

 I have also examined a piece of Schmidt's type specimen, kindly sent me by Dr. Marktanner, and 

 although the examination of a small, dried fragment must necessarily be somewhat deficient, as, on 

 account of contraction, it gives only a rather indistinct idea of the skeleton, I must nevertheless admit 

 Topsent to be right. The fibres consist almost exclusively of strongyla, only a few subtylostyli 

 being found here and there in them; on the other hand subtylostyli are seen to project from the fibres. 

 When upon the whole a group Ectyonince is admitted, Hamigera, according to my examinations, must 

 doubtless be referred to it. Thiele' s species ternatensis, of which it is expressly said that the fibres 

 almost exclusively consist of styli, while at the surface radiating bundles of dermal spicules are found, 

 is surely not to be referred to Hamigera, but must be a Lissodendoryx. When Thiele as the prin- 

 cipal difference between Dendoryx (= JMyxilla) and Hamigera mentions the want of a regular choano- 

 somal skeleton in the latter, this character cannot be used as a generic distinction, as reticular and 

 dendritic skeletons may be found in the different species of as well Lissodendoryx as other genera. 

 When Thiele says, in a foot-note: «Vermutlich werden noch mehrere « «Lissodendoryx»»- Arten in die 

 Gattung Hamigera gehoren-, this is quite correct according to his view, but according to what has 

 been propounded here, such species will just have to be kept in the genus Lissodendoryx. 



lophon Gray. 



The form somewhat varying, in crusting or massive, but not rarely erect, cylindrical or branched, 

 or, finally, more or less regularly leaf-shaped. The skeleton a most frequently irregular, mostly poly- 

 spicular reticulation, without any distinction between primary and secondary fibres ; sometimes longer 

 fibres are present. The dermal skeleton well developed, consisting of bundles of dermal spicules, partly 

 lying horizontally in the membrane, partly erect and penicillate. A rather slight amount of spougiu is 

 found. Spicula: Megasclera : the skeletal spicules styli, most frequently more or less spined, sometimes 

 smooth, the dermal spicules diactinal, strongyla or most frequently tylota, oftenest zvith slightly spined 

 ends; microsclera anisochela; palmatce of a characteristic form with the smaller end provided with a spur, 

 and almost always bipocilla, which may be somezvhat varying in form. 



The genus lophon is an especially distinctly characterized genus, and the distinct characters 

 are found in the microsclera. To be sure, chelae of the same form as in Lophon and bipocilla are 

 again found in Pocillon, which is the pendant of lophon among the Ectyonince, but surely these two 

 genera are also, in spite of the grouping, very closely allied to each other. The peculiar chela is 

 always present in lophon, while bipocilla may be wanting in a few cases, and therefore the chela is 

 the form of microsclera most characteristic of the genus. This chela is never found in any other 



