ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 241 



The whole of the digestive tract is, from the second segment to the 

 amis, clothed internally by a simple epithelial layer, and this is certainly 

 ciliated; below it is a nucleated membrane, which serves as a tnnica 

 propria, and also forms the inner wall of the blood-sinus ; externally to 

 this is a similar membrane, and the two are connected by rare filaments of 

 connective tissue. Outside the muscular layer in some segments of the 

 body there are the chloragogue cells, which are attached by a few processes 

 to the enter wall of the blood-sinus, an arrangement which has not been 

 observed in other Annulates. 



Priapulidae from Cape Horn.* — M. J. de Guerne reports that fourteen 

 Priapulids were obtained by the mission to Cape Horn ; of these, one is 

 doubtful, two belong to Priapidus tiiberculatospinosus obtained by Sir J. 

 Eoss, and the remainder to a new species — Priapuloides australis ; it is 

 much like the northern form P. typicus, but is distinguished by its smoother 

 proboscis, and the larger development of its branchial appendages. The 

 author gives a short account of its structural characters, and points out that 

 it affords an interesting example of the presence in south-polar regions of 

 forms which are almost identical with northern species. 



/3. NemathftlmiTitlies. 



Strongylns arnfieldi and S. tetraeantlnis.t — Dr. T. S. Cobbold 

 describes the morphology of the hood and its rays of Strongylns arnfieldi, 

 as well as the position of the vulva, and the structure of the embryo, con- 

 trasting them with those of allied forms. 



The author's observations on the four-spined Sirongylus show : — 



(1) The eggs are expelled from the parent in a state of fine yolk-cleavage. 



(2) The embryos are formed after egg-expulsion, and in a few days escape 

 from their envelopes, undergoing a primary change of skin in the moist 

 earth during warm weather. (3) 'ihereafter they live many weeks as 

 rhabditiform nematoids. (4) In all likelihood an intermediary host is 

 unnecessary. (5) The rhabditiform larvfe are passively transferred to 

 their equine bearer either with fresh-cut fodder or whilst the animals are 

 grazing. (6 ) Transferred to the intestinal canal they enter the walls of 

 the c£ecum and colon, encyst themselves, and undergo change of skin. 

 (7) Their presence in the intestinal walls is associated with certain patho- 

 logical conditions, frequently fatal to the bearer. (8) Ordinarily the 

 young worms perforate their cysts and immigrate to the lumen of the 

 intestine ; indications of sex appear at this the Trichonema-stage. (9) They 

 next form cocoons by the agglutination of vegetable debris within the 

 intestine, and undergo a third ecdysis with intestinal metamorphosis, 

 (10) The formation of the internal sexual organs and the completion of 

 the definite form is accomplished within the colon of the host. 



New Neniatoid.| — Prof. E. Leuekart states that during the larval stage 

 of CeLidamyia pini, a nematoid worm, which calls to mind Spihserularia, is to 

 be found in its ccelom ; the name of Asconema gihhosum may be given to this 

 new form. In addition to the peculiarities of the generative apparatus, the 

 enteric tract, which has neither mouth nor anus, is remarkable for not 

 forming a tube, biit a solid cord formed of large cells rich in granules, 

 which calls to mind the so-called cell-body of Mennis albicans ; the ends of 

 the cord are attached to the body-wall ; the rudiment of a pharynx can be 



• Comptes Eendus, ciii. (1SS6) pp. 760-2. 



t Joum. Linn. Soc. Lond. (Zool.), xix. (lSSt3) pp. 284-93 (1 pi.). 

 t Zool. Anzeig., ix. (18S6) pp. 744-6; aud Bcr. Yorhaudl. Sachs. Gesell. Leipzig. 

 1886 (1SS7) pp, 356-65. 



