214 SUJIJIARY OF CURRENT RESEARCHES RELATING TO 



branchipodiform furca rejiresent the telson of Malacostraca. The anus 

 is also ventral. 



The brain is much more highly differentiated than that of Phyllopods, 

 and approaches that of Malacostracans. The mid-brain with the olfac- 

 tory centres agrees in the presence of " olfactory glomeruli " with the 

 olfactory lobes of Isopoda and Podophthalmata. The hind-brain (ganglia 

 of the second antennse) lies on the a'sophageal commissure, and has a 

 slightly developed sub-oesophageal transverse commissure in front of 

 that of the mandibular ganglia. The mandibular and maxillary ganglia 

 are quite distinct, as in Ajpseudes and Sphaeroma. So too are the thoracic 

 ganglia. Behind the six abdominal ganglia, there is in embryo and 

 larva the rudiment of a seventh (as in Spfiaeroma). This degenerates. 

 On the median surface of the stalked eye, between two protuberances, 

 there is a special sense-organ of unknown import (frontal organ ?). The 

 histological characters of eye and optic ganglion most closely resemble 

 those of the Mysidse. 



The masticatory apparatus in the stomach is complex, as in Mala- 

 costraca. Two cardiac teeth, a bristle-bearing ridge on the right side, 

 two pairs of pyloric sieves, and a funnel-groove extending far into the 

 intestine, are demonstrable. 



The liver consists of two anterior sacs entering the head, and three 

 pairs extending posteriorly to the last abdominal segments. Mid-gut 

 and posterior liver-sacs are inclosed in a perivisceral connective-tissue 

 which also surrounds the reproductive glands. The cells thereof are 

 filled with fat-spherules of nutritive import in the fasting period. 

 Pregnant females and mature males gradually use this material, and as 

 it disappears the perienteric cellular strand shrivels, and the vascular 

 space enlarges in proportion. At the end of the mid-gut there opens a 

 csecum, which lies above the rectum. The high cylindrical cells of this 

 structure are continued far forward on the dorsal wall of the gut. 



Besides the antennary gland there is a much reduced shell-gland, 

 and eight pairs of limb-glands. 



The heart extends from the maxillary region to the fourth abdominal 

 segment ; it has seven pairs of ostia, of which four to six are small and 

 dorsal, the others lateral. Besides an anterior and posterior aorta, 

 there are branched arteries in both pairs of antennae and in the 

 abdomen. 



The reproductive ducts are as in Malacostraca. The females carry 

 eggs and young in a sort of basket formed between the lamellar 

 thoracic limbs and their bristle-fans. Even the hatched and moulting 

 larvse are sheltered therein. 



The Leptostraca form the first main division of the Malacostraca. 

 The fossil ArcliEeostraca (Ceratiocaridse, &c.) belong to the same series 

 as the Leptostraca, as the mobile head-valve shows. They cannot, how- 

 ever, be included in the same order. The general structure, the form of 

 the mouth-parts and appendages, the numbers of the segments, may have 

 been very different. The memoir is copiously and beautifully illustrated. 



Marine Ostracoda.* — Prof. C. Claus makes a brief communication 

 in reference to a recent work by G. O. Sars on Mediterranean Ostracods. 

 In this work Sars has entirely overlooked three important memoirs by 

 Prof. Claus on Cypridinae, Halocyprinidse, and the general genealogy of 



* Arbeit. Zool. Inst. Wien (Claus), viii. (1888) pp. 149-54. 



