ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 621 



situated. The body-parenchyma consists of a reticular nervous 

 tissue, and the size of the meshes varies in different parts of the 

 body. 



The nuclei of the muscular fibres are usually situated in proto- 

 plasmic prominences at the side of each fibre ; the fibres divide at 

 their ends into several branches, between which there are protoplasmic 

 remnants of, probably, connective tissue 



What previous writers have called suckers are really ciliated 

 glandular sacks ; their walls are not, as Graff states, muscular, but 

 they are glandular internally, and are covered by a ciliated cuticle, 

 which has a striated appearance owing to the penetration of the cilia 

 into the tissue. They differ from the nephridia of Annelids by not 

 communicating with the body-cavity, but this may be explained by 

 the degeneration or partial disappearance of the body-cavity ; their 

 only point of resemblance to the segmental organs described by Huet 

 in Isopods lies in this want of an internal cavity. 



The hooks are solid, consisting of an outer homogeneous and an 

 inner fibrous layer. In ilf. giganteum the glandular mass surrounding 

 them is particularly well developed ; and its cavity communicates with 

 the sea-water by the canal of the chief hook The alimentary canal is 

 divisible into the proboscidial canal with the oesophagus, the stomach, 

 the intestinal branches from the stomach, and the rectum with the 

 cloacal canal. 



Complemental males were found in M. giganteum, M. gigas, and 

 M. carpenteri ; they are quite similar in structure to the hermaphro- 

 dites, except that where the latter have ovaries the males have tubes 

 with slightly developed cells, so that they have a certain resemblance 

 to young ovaries ; the dorsal oviduct (uterus) is feebly but the lateral 

 oviducts are well developed. The author disagrees with Beard as 

 to the secondary origin of the hermaphroditism of Myzostomida, 

 inasmuch as the dioecious species are the most parasitic, and the 

 rudiments of testes in M. cysticolum appear to be rather remnants of 

 an androgynous stage than budding developments of male organs. 



As to the difficult question of the systematic position of the -group, 

 the author is of opinion that they are distinct from but allied to 

 Chretopods; while they show a tendency towards certain Arachnids 

 (Linguatulida, Tardigrada, and perhaps Pycnogonida) and Crusta- 

 ceans. They are sprung from the Trochophora, and, among Archi- 

 annelids, are related to Histriodrilus. 



New Rotifer-* — Under the name of Stephanops leydigii Dr. O. 

 Zacharias described a short time ago a new rotifer which has since 

 been independently described by Mr. J. E. Lord. It is almost cer- 

 tain that the species is distinct from the S. longispinatus of Tatem. 



New Floscule-f — Floscularia millsii resembles Stephanoceros in 

 its elongated form and very attenuate lobes, as well as in its motion, 

 but Dr. D. S. Kellicott regards it as belonging to the genus Floscu- 

 laria on account of its general structure. The presence of a single 



* Zool. Auzeig., ix. (188G) pp. 318-20. 



t Pfoo. Amer. Soc. Micr., 8th Ann. Meeting, 18S5, pp. 48-50 (1 fig.). 



