162 



nedimod dettes udvidede Del (Maven), hvor den deler sig 

 i to stærke Grene, en til hver Side, hvilke igjen forene 

 sig i et temmelig stort Ganglion, strax nedenfor det Sted, 

 hvor den egentlige Tarm tager sit Udløb. Fra dette 

 Ganglion udgaar foruden Hovedstammen, der langs Tar- 

 men fortsætter sit Løb til dennes Ende, en Mængde mindre 

 Grene til de omkringliggende Dele. Paa de Grene, der 

 løbe ved Siden af den udvidede Tarmdel, findes flere 

 mindre Ganglier. Saavel fra disse, som fra selve Grenene, 

 udgaa en stor Mængde mindre Grene dels til Maven, dels 

 til Huden (ikke Chitinhylstret) og dels til Generations- 

 organerne* Ogsaa paa disse Smaagrene ere Ganglier, 

 der ved deres Grene anastomosere med hinanden og danne 

 udbredte Nerveplexuser. Paa den øverste Del af Bug- 

 strengen saae vi ingen Ganglier, men mange Sidegrene, 

 som gik til Spiserøret og den dette omgivende Hud. Bug- 

 strengen tilligemed dens Grene have en yderst finstribet 

 Structur, imedens der i Ganglierne findes mange Ganglie- 

 celler med deres Udløbere. 



Hanner af Dyret have vi ikke iagttaget. 



Pennella Balænopteræ findes paa Vaagehvalen (Ba- 

 lænoptera rostrata, Fabr.), i Nærheden af Kjønsorganet. 

 Stundom forekomme flere paa et Dyr; men i det Hele 

 taget er dens Forekomst sjelden. Den borer sig fra 1—3 

 Tommer ind i Spækket — kommer aldrig ind til Kjødet 

 — og danner derved tildels bugtede Gange. Hvor Hovedet 

 og Hornene findes, der er Spækket ramolleret til en tyk 

 Vællings Consistentse og i et Omfang af en lille Valnøds. 



Paa denne vor Pennella snylter en Cirripede (Con- 

 choderma virgata, Spengl.) meget hyppigt (Fig. 1 h), og 

 det er ikke alene et enkelt Dyr; men ofte ser man 

 paa den tynde Brystdel indtil 7 fuldvoxne Exemplarer, 

 hvoraf enkelte indtage, en Længde af 40 Mm.; hyppigst 

 sidde de dog nede ved Æggetraadenes Begyndelse, hvor 

 de ligeledes kunne danne en Klynge af 5—6 Exemplarer. 



Vi have taget f or skj ellige Maal af to fuldvoxne 

 Exemplarer. 



A. B. 



Dyrets hele Længde 320 Mm. 300 Mm, 



Den smalere Brystdels Længde 195 — 190 



„ — . — Tykkelse .... 2 — 2 — 



Den bredere Brystdels Længde ..... 75 — 62 — 



i, — — Tykkelse .... 6 — 6 — 



Abdominaldelens Længde 45 — 42 



Hovedets Længde 7 — q 



— Bredde ♦ 8 — 7 



Hornenes Længde 15 — 14 



— Tykkelse 2— 2 — 



Pennella Balænopteræ adskiller sig fra P. erassicornis, 

 Steenstr. & Lütken, derved, at den er en halv Gang saa 

 lang, har et mere fremtrædende Hoved, der er baade 



oesophagus until down towards the enlarged part of the 

 latter (the stomach), where it divides itself into two strong 

 branches, one on each side, which again unite in a rather 

 large ganglion immediately below the place where the proper 

 intestine takes its issue. From this ganglion — besides 

 the main trunk, which continues its course along the 

 intestine to the extremity of the latter — proceed a num- 

 ber of smaller branches to the circumjacent parts. On 

 the branches which run by the side of the enlarged part 

 of the intestine, there are several smaller ganglia. As 

 well from these as from the branches themselves, there 

 issue a great number of smaller branches, partly to the 

 stomach, partly to the skin (not the chitinous envelope) 

 and partly to the organs of generation. Also on these 

 small branches there are ganglia, which, by their bran- 

 ches, anastomose with each other, and form extended 

 plexuses of nerves. On the upper part of the ventral 

 cord, we did not perceive any ganglia, but many lateral 

 branches going to the oesophagus and to the skin sur- 

 rounding it. The ventral cord together with its branches, 

 have an extremely fine-striped structure; while in the 

 ganglia, there are many ganglionic cells with their rami- 

 fications. 



We have not observed any males of this species. 



Pennella Balænopteræ is found on the Vaage Whale 

 (Balænoptera rostrata, Fabr.), in the vicinity of the organ 

 of generation. Occasionally there are several on one 

 animal; but, on the whole, its occurrence is rare. It bores 

 itself from 1—3 inches deep in the blubber — never 

 comes into the flesh — and sometimes, in so doing, forms 

 sinuous passages. Where the head and the horns are 

 found, there the blubber is softened to the consistence 

 of a thick gruel, and to the extent of the circumference 

 of a small walnut. 



On this our Pennella, there very often subsists a 

 parasite Cirripede (Conchoderma virgata, Spengl fig. 1 h), 

 and it is not only a single animal, but we often find, on 

 the thin thoracic part, as many as 7 full grown spe- 

 cimens, of which some have a length of up to 40 Mm. ; they 

 most frequently, however, are situated down at the com- 

 mencement of the ovisacs, where they likewise can form 

 a cluster of 5— 6 individuals. 



We have taken various measures of two full grown 

 specimens. 



Whole length of the animal 



Length of the narrower thoracic part ♦ 



Thickness 



Length of the broader thoracic part . . 



Thickness 



Length of the abdominal part ...... 



Length of head ' 



Breadth - — . 



Length of horns 15 — 



Thickness — ............. 



Pennella Balænopteræ differs from 

 Steenstr. & Lütken, by being half as long again, and 

 having a more advancing head, which is both broader 



A. 



B. 



320 Mm. 



300 Mm, 



195 — 



190 - 



2 — 



2 — 



75 — 



62 - 



6 — 



6 - 



45 — 



42 - 



7 — 



6 - 



8 - 



7 - 



15 - 



14 - 



2 — 



2 — 



from P. 



erassicornis 



V 





