Miscellaneous, 



67 



Leuckart and Mecznikow, presents us, among the Nematode worms, 

 with a very similar example of dimorphism of sexual forms. — Bibl. 

 Jlniv. 1865, Bull. Sci. pp. 154-160; abstract of ' Beitrage zur 

 Naturgeschichte der Hydromedusen, Heft 1 . Die Familie der RuS' 

 selquallen. Leipzig, 1865. 



On some Crustacea of the French Coasts. 

 By M. Hesse. 



In a ninth memoir on new and rare French Copepod Crustacea, 

 M. Hesse describes numerous species of this class, most of which 

 are found living in the interior of various Ascidians. The species be- 

 long to the genera Boropygus and Dispontius of Thorell and to four 

 new genera proposed by the author. 



Of the genus Boropygus the author describes twenty-one species, 

 four of which had previously been observed by Thorell. He gives 

 the following general table of their characters : — 



terminating in a rounded ^^'2'= ^/ '^^<^^io, puUx (Thor.), 

 point ; appendages straight, TIZT% ''''''^*' ^^^^^m^'^^ 



unarmed,^vith^r without \ ^''^'^"*' °*^^^^«*' rotundm. 



hairs; posterior thoracic ^^^x^ri^., d. verrucosus, albidm, vi- 



ridis, gibbosusy tumef actus. 



Abdominal , 

 extremity 



process 



terminated by a small ca- 

 vity; appendages recurved 

 and hooked, armed with 

 points ; posterior thoracic 

 process 



'large: D. gibber (Thor.), psyllus 

 (Thor.), auritus (Thor.). 



small : D. acutus, refiexus. 



wanting : D. macroone, rufescens, 

 coccineus. 



Most of these species occur in simple Ascidians ; but the habitat 

 of D. oblongus is said to be Polyclinium stellatum ; D. tumef actus 

 occurs in '' an incrusting pustular Ascidian of a brown colour,*' found 

 on a Maia squinado ; B. rufescens inhabits a reddish, pustular, in- 

 crusting Euccelinus ; and B. defiexus was found under the cortical 

 envelope of a zoophyte attached to the feet of a Maia squinado. 



Of the genus Bispontius the author describes Thorell' s species 

 B. striatus, and two new ones, B. marginatus and B. conspicuus. 



Those which form the types of new genera are : — 



1. Gastrodes, Hesse. 

 Closely aUied to Botachus. Female. Body elongate, narrow in 

 front, enlarging gradually to base of thorax ; thorax of six segments; 

 abdomen narrow, cylindrical, of five segments, the last terminated 

 by four very strong opposed claws, which may be prehensile. An- 

 tennae moderate, basal joint large and long ; stem cylindrical, eight- 

 jointed. First footjaw long and slender, terminated by a hooked 

 claw ; second and third stouter and shorter. Natatory thoracic feet 

 biramose, furnished with points and hairs. Eye single,* in the middle 



