506 SUMMARY OF CURRENT RESEARCHES RELATING TO 



is often used for quite different pairs ; tlius, the third maxilliped of a 

 Decapod corresponds to the second thoracic foot of an Amphipod, 

 while the first thoracic foot of an Isopod is something altogether 

 different to the first thoracic foot of a Decapod. Certain modifications 

 in the received nomenclature are therefore proposed. All the appen- 

 dages hitherto called maxillipeds and thoracic feet are grouped 

 together under the name of trunk-feet or cormopods, and of these 

 there are in all Malacostraca, with but very rare exceptions, eight 

 pairs. This view is based on the considerations that in the genus 

 Nehalia the body is easily divisible into head, trunk, and tail ; the 

 first, in which there are no signs of segmentation, carries the eyes, 

 antennas, mandibles, and maxillas, and is distinctly separated from the 

 trunk, which consists of eight short segments : these all carry appen- 

 dages which resemble one another, and differ from those in front of or 

 behind them ; further, they correspond to what, in the Malacostraca, 

 are spoken of as maxillipeds and thoracic feet. With the exception 

 of the autennfe, we always find in the appendages of the Malacostraca 

 an endopodite and an exopodite ; but it is only in the cormopods that 

 we find an epipodite develojied. 



The author points out the differences between the antennular and 

 the succeeding appendages, and comes to the conclusion that they are 

 not equivalents of those that follow them, and that it would be well 

 not to regard them as appendages at all. He is inclined to think that, 

 like the eyestalks, they are appendage-like sensory organs. The suc- 

 ceeding parts are then discussed ; Boas states that the cormopods 

 consist of a seven-jointed endopodite, an epipodite arising from the 

 outer side of the first joint, and an exopodite from the second joint 

 of the endopodite. One or both of these latter are frequently absent ; 

 some of the joints of the endopodite may be fused, and the basal joint 

 is often more or less closely connected with the trunk-skeleton. 

 After a detailed account of what is seen in the different orders, we 

 come to the caudal feet ; of these the Malacostraca have typically 

 six pairs, and behind them there is a footless segment. 



The different orders are next discussed in detail, and the whole 

 concludes with a general review of the groups, which must be of the 

 highest value to the scientific carcinologist. 



Circulatory Organs of Stomatopoda.* — Prof. C. Glaus has been 

 making some observations on the larval stages of Alima and Ericlithus, 

 the structure of whose hearts he describes in detail. Dealing also with 

 the cii-culatory vessels, he comes to the conclusion that the whole system 

 of cerebral vessels with its numerous coils, many of which are mere 

 capillaries, may be regarded as a large vascular loop connected with 

 the aorta, just as the much simpler vascular loops in the ganglia of the 

 ventral chain may be looked upon as appendages of the sternal artery. 

 He regards as certain the homology of the anterior widened portion 

 of the heart and its connected pair of arteries in the Stomatopoda 

 with the heart of the Decapoda, and describes the ventral artery 

 which has been overlooked or denied to exist as being a median 



* Arbeit. Zool.-Zoot. Inst. Wurzburg, v. (1883) pp. 1-12 (3 pis.). 



