748 PROCEEDINGS OF THE NATIONAL MUSEUM. 



gium in the female oontains a sinjjle sporosac with a siiifijle ovum; and this ovum, 

 after a time, becomes extra-capsular in order to undergo within an acrocyst some of 

 the earlier stages of its development. 



This author also says Gopjmiia is found on Sertularia ahietina and 

 Hi/draUmania falcata from dee[) water. 



The Hydranths are furnished with a verticel of filiform tentacles disposed around 

 tlie base of a short conical hypostome. They are, however, often imperfect and 

 ajjparently destitute of mouth and tentacles. 



In 1865, under the name Lafob'a cnZcarato, Alexander Agassiz' de- 

 scribes a species which ])roduced medusa?. It is almost certain, how- 

 ever, that this species would not be included in the family Lafoiiidie as 

 at i)reseut understood. 



In 1875 Canon Korman^ described a new genus, Scaptis, as, foWovf 8 : 



Zoophyte in the form of a spongious mass rolled in cylindrical form around the 

 stems of branching Hydrozoa (Acrypiolaria) and consisting of a series of somewhat 

 closely packed subquadrate hydrotliecie, closed in 'above, except at the center, 

 where the hydrotheca jtrojectod in the form of a short, simple cylindrical horny 

 tube. 



In describing the species Scapus tuhulifer, the author says that these 

 '' hydrotheca-" are packed closely together, and that they are "bottle- 

 shaped, expanded below and forming the mass, and contracted above 

 into narrow projecting tubes." If Canon Norman's interpretation is 

 correct, we have here the only "bottle-shaped" hydrothecic known to 

 me. The figure given would indicate that the specimen upon which it 

 was based was dried. If this is so, it might be hard to determine 

 whether the bottle shaped structures were hydrotheca* or gonangia. 

 In view of later discoveries, it seems not unlikely that the latter is the 

 case. Indeed, Marktanner-Turneretscher does not hesitate to call them 

 gonangia. 



Norman hat unter dem Namen Scapus tuhidifer ein anderes Aggregat von Gono- 

 theken beschrieben, welch er auf Acri/ptolaria exserta angctroffen hat; es besteht 

 aus lauter Gonotheken, zwischen denen keine Hydrotheken stehen.' 



Allman, writing in 1877, in discussing Gryptolaria conferta* says: 



On the branches of the specimen here described there occurred here and there cer- 

 tain very remarkable bodies the real nature of which I have not succeeded in plac- 

 ing beyond doubt. They are of an irregular fusiform shape, and at the spots where 

 they occur surround the branch like minute sponges. A closer examination shows 

 them to consist of a multitude of flask-shaped, apparently chitinous receptacles, 

 adnate to one another by their sides, and sjiringing by a narrow base from an irreg- 

 ular network of tubes which encircle the branch. The distal extremity of each is 

 prolonged into a free neck-like extension, which terminates in an even circular 

 orifice. 



' Xorth American Acalephpp, Illustrated Catalogue, Mus. Comp, Zool,, 1865, No. II, 

 p. 124. 



- Submarine Cable Fauna, Ann. and Mag. Nat. Hist., 4th set., XV, p. 173, pi. xii, fig. 3. 



^Hydroiden von Ost-Spitzbergen, Zool. .Jahrb., YIII, Abth. f. Syst., p. 403. 



^Iteport of the Hydroida collected during the Exploration of the Gulf Stream, 

 Mem. Mus. Comp. Zool., 1877, No. 2, V, p. 18. 



